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BMI tests 'miss' over a quarter of obese children

Mon, 20/10/2014 - 13:00

"Quarter of obese children missed by BMI tests," the Mail Online reports.

The headline was prompted by a review that combined the results of 37 studies in more than 50,000 children and found body mass index (BMI) is an imperfect way of detecting excess body fat.

The study estimated more than a quarter of children (27%) with excess body fat might not be classified as obese when using BMI measurements alone.

This may mean the missed children don't get the same support to achieve a healthy weight as those correctly identified as obese, and so remain at a higher risk of developing a range of weight-related diseases, such as type 2 diabetes.

BMI has long been known to be a relatively blunt tool in terms of accurately assessing body fat, as demonstrated in a similar study in 2012. However, this latest study puts a specific figure on the imperfection.

That said, BMI remains a very useful tool. It provides a reasonably accurate method to estimate obesity rates at a population level, taking just minutes to complete.

Other methods can be more resource and time consuming (hydrostatic weighing), or can have large margins of error if not done correctly (skin callipers).

Overall, this study adds to the evidence of BMI's "bluntness" by quantifying the possible impact of the inaccuracy.

If you are worried about your child's weight, contact your GP. They should be able to make a more detailed assessment.

 

Where did the story come from?

The study was carried out by researchers from the US and Czech Republic. No funding source was reported.

It was published in the peer-reviewed medical journal, Pediatric Obesity.

The Mail Online's coverage was broadly accurate, though if we were being really pedantic we would point out to the headline writers that 27% is not the same as 25%.

 

What kind of research was this?

This was a systematic review and meta-analysis of studies assessing the diagnostic performance of BMI to detect excess fat in children up to the age of 18.

systematic review seeks to identify and pool the results of all published material on a specific topic, and is an effective way of summarising lots of research evidence. A meta-analysis is a related statistical exercise, where the results of studies are pooled. 

Excess fat in people raises the risk of many weight-related diseases, such as diabetes and heart disease. Detecting excess fat in children helps identify those most at risk of damaging their health.

The researchers point out the ideal way of identifying obesity in children and adolescents has not been determined, although BMI is the most widely used screening tool.

This involves weighing and measuring the height of a young person to estimate their BMI. The BMI is then compared against standard cut-offs, which categorises the person as either underweight, a healthy weight, overweight or obese.

In England, this is the approach adopted by the NHS National Child Measurement Programme.

 

What did the research involve?

The researchers searched electronic medical databases for studies assessing the performance of BMI measurement compared with other measures of body fat in people less than 18 years of age.

They then pooled the individual study findings using a meta-analysis to give an overall estimate of how well BMI identified people with excess body fat.

All of the studies included had to compare measuring body fat using BMI with a different reference method, such as DEXA.

Study authors of relevant articles published on the topic were contacted to source additional relevant literature and supplement the electronic database searches.

The main analysis reported the sensitivity and specificity of using BMI to detect excess fat in males and females.

The analysis explored variation between the studies with regard to differences as a result of race, BMI cut-off, BMI reference criteria, and the reference standard for assessing fatness.

 

What were the basic results?

The analysis included 37 studies involving 53,521 patients. The average age in the studies ranged from 4 to 18 years.

The main finding was that commonly used BMI cut-offs showed a pooled sensitivity to detect high fatness of 0.73 (95% confidence interval [CI] 0.67 to 0.79) and a specificity of 0.93 (95% CI 0.88 to 0.96).

This means that BMI correctly identified children with high fat levels 73% of the time, and correctly identified children without high fat levels 93% of the time.

On the flip side, this means up to 27% (100% minus 73%) of children with high fat levels were not correctly identified using BMI, so 27% was the false positive rate.

There was moderate variation in the pooled results as a result of the confounders mentioned above.

 

How did the researchers interpret the results?

These results led the researchers to conclude that, "BMI has high specificity but low sensitivity to detect excess adiposity [body fatness] and fails to identify over a quarter of children with excess body fat percentage."

 

Conclusion

This systematic review and meta-analysis showed using BMI to detect excess body fat in children up to the age of 18 was not perfect. It estimated more than a quarter of children with excess body fat might not be classed as obese using BMI measurements alone.

This may mean they don't get the same help and support to achieve a healthy weight as those correctly identified, and so remain at a higher risk of developing a range of weight-related diseases.

BMI is known to be a far from perfect measure of body fatness, but is often a useful start, so the main conclusion of the research will be nothing new to many health professionals.

However, this study has put a specific figure on the imperfection: more than 25% are incorrectly given the all-clear when their weight may be harming their health.

England's current screening of children for excess body fat, the National Child Measurement Programme, uses BMI as its main measure, so this is very relevant to England's youth.

The way excess body fatness is assessed in this programme is regularly assessed, and this study may contribute to the evidence base considered at the next review of the methodology.

Measuring body fat in children on a large scale is a challenge, and the best way to do this is likely to be balancing accuracy with pragmatism. Some measures of body fat are time consuming to perform and, in the context of a busy school environment, this may be influential.

Overall, this study raises a known issue with using BMI to assess body fat in children, but adds to the evidence by quantifying the possible impact of the inaccuracy.

If you have any concerns about your child's weight, your GP will be able to assess whether their weight may be affecting their health and can offer help and support.

Analysis by Bazian. Edited by NHS ChoicesFollow Behind the Headlines on TwitterJoin the Healthy Evidence forum.

Links To The Headlines

Quarter of obese children missed by BMI tests could be at risk of diabetes and heart disease, scientists warn. Mail Online, October 17 2014

Links To Science

Javed A, Jumean M, Murad MH, et al. Diagnostic performance of body mass index to identify obesity as defined by body adiposity in children and adolescents: a systematic review and meta-analysis. Pediatric Obesity. Published online June 24 2014

Categories: NHS Choices

Viagra could double up as heart failure drug

Mon, 20/10/2014 - 11:30

"Sex pill Viagra could help men suffering from heart disease," reports the Mirror. This headline follows a new review into the potential heart benefits of the active ingredient in erectile dysfunction drugs such as sildenafil (Viagra), called phosphodiesterase type-5 inhibitors (PDE5is).

PDE5is work by helping blood vessels dilate, which in the case of erectile dysfunction increases blood flow to the penis.

Researchers were interested in whether this dilation effect could have benefits for certain heart conditions, such as heart failure, where the heart struggles to pump blood because of previous damage to heart muscles.

They pooled the findings of 24 randomised controlled trials (RCTs), which suggested PDE5is were better than placebos at improving some measures of heart function in men with early signs of heart disease. 

Commonly reported side effects included flushing, skin rashes and headaches.

Importantly, the study did not assess the drugs' effects on the heart versus treatments currently available to treat or prevent heart conditions.

This means we that cannot say whether they are safer or more effective than existing drugs. PDE5is are currently unlicensed for the treatment of heart failure.

 

Where did the story come from?

The study was carried out by researchers from Sapienza University of Rome and was funded by a Ministry of Research Grant.

It was published in the peer-reviewed medical journal BioMed Central. This is an open access journal, so the study is free to read online.

Generally, the media reported the story accurately. The Mirror, for example, chose its words carefully in saying that, "The sex pill could help men suffering from heart disease". Using the word "could", rather than "does" or "would", adds a necessary element of uncertainty.

The Mirror's reporting of the study was of a reasonable quality, and included relevant quotes from the study's lead author and a useful explanation of a subtype of heart disease known as left ventricular hypertrophy. In many ways, the paper has put its "posher" broadsheet rivals to shame with its reporting.

 

What kind of research was this?

This was a systematic review and meta-analysis of RCTs to assess the effects of the group of drugs known as PDE5i on heart health and function.

These drugs are currently licensed to treat erectile dysfunction, and include sildenafil, which carries the widely known brand name Viagra.

PDE5is work by helping blood vessels relax and dilate, increasing blood flow through the vessels.

This effect also lowers blood pressure, so these drugs are currently contraindicated or used with caution in people with heart disease, including those who have had recent strokes or heart attacks, as the effects are unknown.

However, various research studies have continued to investigate the possibility these drugs could have a beneficial effect on heart function. This review has looked into their effect on cardiovascular outcomes further.

A systematic review of RCTs is one of the most robust study designs aimed at proving whether something works or does not work. It can also tell us whether there is simply not enough evidence to tell one way or the other.

 

What did the research involve?

The research team searched online medical research databases for placebo-controlled RCTs evaluating the effectiveness and safety of PDE5i for a range of heart-related measures.

They then pooled the results of a number of RCTs to create combined estimates of the effects of PDE5is in different people with different heart characteristics.

Some of the main measures they looked at to test if PDE5is improve heart health were:

  • cardiac mass and structure – abnormally high mass can impair the function of the heart
  • cardiac performance
  • afterload – the force developed in the wall of the left ventricle (the large heart chamber that pumps blood to the rest of the body) during blood ejection
  • endothelial function – the endothelium is the inner lining of blood vessels
  • heart rate and blood pressure

RCT results were divided into a number of subgroups to compare:

  • people with moderate-severe left ventricular hypertrophy (LVH) versus those without – LVH is where the wall of the left ventricle is enlarged and thickened, meaning it is under strain and can't pump as effectively; this is often an early sign of heart disease caused by high blood pressure
  • left versus right heart disease (damage to the left or right ventricles of the heart)
  • cardiac disease versus non-cardiac disease (conditions not directly related to the heart that can impact on heart functions, such as anaemia or kidney disease)
  • age – 60 and under, versus over 60

All studies were RCTs, double-blind and placebo-controlled. Four studies were crossovers with variable washout periods (a period during a clinical trial where no treatment is given, allowing the effects of previously administered drugs to be "washed out" of the body).

14 trials received funding from the pharmaceutical companies Pfizer and Eli Lilly or foundations.

The main analysis compared the results of PDE5i with a placebo across the different subgroups and combined overall.

 

What were the basic results?

The searches returned 24 relevant RCTs containing 1,622 participants – 954 randomised to PDE5i and 772 to placebo.

The main results favoured PDE5i compared with placebo across a range of heart outcomes. Sustained PDE5 inhibition produced:

  • an anti-remodelling effect by reducing cardiac mass (−12.21 g/m2, 95% confidence interval [CI] −18.85, −5.57) in people with left ventricular hypertrophy, and by increasing end-diastolic volume (volume after heart filling: 5.00 mL/m2, 95% CI 3.29, 6.71) in people without LVH
  • an improvement in cardiac performance by increasing cardiac index (0.30 L/min/m2, 95% CI 0.202, 0.406) and ejection fraction (3.56%, 95% CI 1.79, 5.33) – both measures related to how much blood is ejected into the body's circulation
  • no changes in afterload
  • an improvement in flow-mediated vasodilation (3.31%, 95% CI 0.53, 6.08)

The commonest side effects were those known to be associated with PDE5i, such as flushing, headache, nosebleeds and gastric symptoms.

 

How did the researchers interpret the results?

The researchers concluded that, "PDE5i could be reasonably offered to men with cardiac hypertrophy [enlarged heart muscle] and early-stage heart failure.

"Given the limited gender data, a larger trial on the sex-specific response to long-term PDE5i treatment is required."

 

Conclusion

This systematic review of 24 RCTs indicated PDE5is were more effective than placebos at improving specific measures of heart health and were broadly safe.

PDE5is lower blood pressure, so these drugs are currently contraindicated or used with caution in people with cardiovascular disease, including those with low blood pressure and a history of stroke or heart attack, as the effects are unknown.

However, various research studies have continued to investigate the possibility that these drugs could have a beneficial effect on heart function.

This review has looked into their effect on cardiovascular outcomes further and found some promising results, including that they could be beneficial in people with left ventricular enlargement and high blood pressure.

But the study has only compared PDE5is with placebos, and has not assessed their effects against heart treatments currently available to treat or prevent heart conditions.

Similarly, the studies included varied in terms of:

  • daily dosage of PDE5i
  • length of treatment – from 4-week to 12-month study periods
  • endpoint assessment method
  • age
  • baseline cardiovascular status
  • gender – 8 trials enrolled only males and 16 trials had a mixed population of 540 females and 459 males

Pooling such diverse studies may have papered over some of the cracks and nuances in treatment efficacy and safety. For example, these drugs may work much better in some groups than others, or be less safe in some groups compared with others.

The studies provided a range of clinical data, such as changes in cardiac mass and flow-mediated vasodilation. But it is not clear what impact these measurements would actually have in terms of developing lower levels of heart disease, improving quality of life or extending disease-free life.

Most of the research was in men, so the knowledge about the effects of PDE5i in women are less clear.

Overall, the review suggests PDE5is are better than placebo for improving some measures of heart function, but the clinical implications of these findings are currently unclear.

Despite the review's conclusions that these drugs could have a good safety profile for use in people with certain heart conditions, more research looking at this specific issue is needed.

These interesting findings prompt the need for further research and, for the time being, the current prescribing information, which advises the cautious prescribing of PDE5i in people with existing cardiovascular conditions, is likely to remain in place.   

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Forget sex, Viagra could be used for heart disease. The Times, October 20 2014

How Viagra could help halt heart attacks and strokes, with some doctors saying it should be routinely prescribed. Mail Online, October 20 2014

Sex pill Viagra could help men suffering from heart disease, a study has revealed. Daily Mirror, October 20 2014

Viagra could soon be used for heart disease patients: researchers. The Daily Telegraph, October 20 2014

Links To Science

Giannetta E, Feola T, Gianfrilli D, et al. Is chronic inhibition of phosphodiesterase type 5 cardioprotective and safe? A meta-analysis of randomized controlled trials. BMC Medicine. Published online October 20 2014

Categories: NHS Choices

Exercise data signs could cut sugary drink intake

Fri, 17/10/2014 - 12:00

“Signs warning shoppers how much exercise they need to do to burn off calories in sugary drinks can encourage healthier choices,” BBC News reports. Signs in shops in an area of Baltimore seemed to have led to a change in shopping habits amongst Afro-American teenagers.

Researchers first studied beverage purchases by black teens at six corner stores in Baltimore.

They then tested the effect on purchasing habits of displaying different types of calorie information, such as the number of calories in a sugary drink, or how much walking or running you’d need to do to burn off the calories.

Overall, they found that displaying the information changed beverage purchases, with fewer sugary drinks purchased and fewer large drinks purchased, leading to fewer overall calories.

Environmental interventions, including product information and advertising, are known to have some effect on purchasing intentions, so may be a way to target the obesity epidemic. However, it would be premature to generalise these results to other environments and populations at this stage.

There has been a significant amount of research suggesting that that people habitually underestimate the amount of calories they eat, as well as the amount of exercise required to burn off these calories. Therefore, a case could be made that manufacturers could consider adding information such as exercise data to their products.

 

Where did the story come from?

The study was carried out by researchers from Johns Hopkins Bloomberg School of Public Health, Baltimore, in the US, and was funded by the Robert Wood Johnson Foundation through its Healthy Eating Research programme.

The study was published in the peer-reviewed American Journal of Public Health.

Both the BBC News and the Mail Online's reporting of the study was accurate.

 

What kind of research was this?

This was a type of case-crossover study, which aimed to look at the effect that displaying calorific information in different ways in a small sample of corner stores in the US had on the purchase of sugar sweetened beverages (SSBs) by US teenagers from black minority ethnic groups. 

SSBs that were assessed by the study included “soda”, fruit drinks, sport drinks, vitamin water and “Hug” (a US product similar to Fruit Shoot).

A traditional case-crossover study is one where each individual is being used as their own control. In one circumstance, they will be exposed to the risk exposure (the “case”), and in another they will be exposed to the “control” exposure. In this study, the exposure being altered is calorie information. Though described by the researchers as a case-crossover study, this wasn’t a traditional example of this study type, as they weren’t ensuring that it was the same individuals being exposed to each scenario. Rather, they were looking at the same environment (an area of inner-city Baltimore) after an exposure.

It could also be considered to be a type of “before and after” study, where they are just looking at the differences before and after an intervention.

The researchers say that consumption of SSBs is believed to be an important contributor to adolescent obesity, particularly among minority ethnic groups. The researchers report that SSB consumption makes up 15% of the daily calorie intake of minority adolescents, with black adolescents drinking at least twice the daily maximum of SSBs advised by American guidelines (eight to 12 ounces a day). Understanding the potential for environmental interventions is said to be essential for curbing the obesity epidemic.

 

What did the research involve?

This study was conducted in six corner stores in low-income black neighborhoods in Baltimore over a 10-month period, between 2012 and 2013. The target population was black adolescents aged between 12 and 18.

They investigated the effect of displaying four different types of calorific information on SSBs:

  • absolute number of calories in the drink
  • number of teaspoons of sugar
  • minutes of running required to burn off the calories
  • miles of walking required to burn off the calories

Each of these different pieces of information was displayed on a brightly coloured sign in a prominent location on the fridge containing drinks saying, respectively:

  • “Did you know that a bottle of soda or fruit juice has about 250 calories?”
  • “Did you know that a bottle of soda or fruit juice has about 16 teaspoons of sugar?”
  • “Did you know that working off a bottle of soda or fruit juice takes about 50 minutes of running?”
  • “Did you know that working off a bottle of soda or fruit juice takes about 5 miles of walking?”

The signs were based on the estimate that the average 15-year-old would weigh around 50kg (110lbs).

Information was collected of purchases by black adolescents who appeared to be aged 12 to 18 years. A random sample of 35 adolescent purchases per store per week was collected, with information recorded on whether or not the adolescent purchased a beverage and, if so, what type and size of drink.

Over a four-week period, they collected baseline information of SSB purchases when no calorie information was available. Then the six stores displayed each of the different types of information for two weeks, during which time the information on adolescent purchases continued. There was a one week “washout” period between the different signs, where no sign was displayed. For a final six-week post-interventional period, all calorie information was removed.

They also conducted a sample of interviews, where adolescents were stopped and asked whether they had noticed the signs, understood the information, and whether this had influenced their purchases.

The main outcomes described in the study were:

  • whether an SSB was purchased
  • total number of calories
  • whether a large volume was purchased (above 16 ounces, as there had been recent local efforts to ban these sizes in food establishments)

 

What were the basic results?

Over the course of the study, information was collected on 4,516 purchases by black adolescents, 3,098 of which were for beverages of any type. This included 601 beverage purchases during the baseline weeks, 2,311 beverage purchases spread across all four calorie information interventions, and 186 beverage purchases in the post-intervention period.

During the baseline week, just under three-quarters of purchases included a beverage, 97% of which were for SSBs, just over half of which were large volume SSBs, and mean calories of all beverages was 207kcal (206 for SSB beverages).

During each of the interventions there was a change in beverage purchases, with fewer SSBs purchased, fewer large volume SSBs and fewer beverage calories. For example, across all four interventions, the calorie content of any beverage fell from 207 to 184kcal (206 to 196 for SSBs). The proportion of all beverage purchases that included an SSB fell to 89% and the proportion of SSB purchases that were large volume fell from 55% to 37%.

Even in the post-intervention period, after removing the signs, SSB purchases, volume and total calories remained lower than at baseline.

In the interviews, just over a third of adolescents reported seeing the calorie information displayed, 95% of whom reported understanding them, and 40% said they changed their purchase as a result.

 

How did the researchers interpret the results?

The researchers conclude that, “Providing caloric information was associated with purchasing a smaller SSB, switching to a beverage with no calories, or opting to not purchase a beverage; there was a persistent effect on reducing SSB purchases after signs were removed”.

 

Conclusion

This is an interesting study exploring how displaying different types of calorie information in corner stores may change SSB purchases among minority ethnic groups in the US.

Environmental interventions, including product information and advertising, are known to have some effect on purchasing intentions, so may be a way to target the obesity epidemic.

Many experts argue that we are now living in an "obesogenic environment", where the everyday world around us encourages unhealthy food. For example, a study we covered in March 2014 found an association between the number of fast food outlets in a given area and body mass index.

However, little can be firmly concluded from this study. It has focused on studying only black adolescents in one specific region of the US, and has only looked at the effect of the interventions in six corner stores. We don’t know the effect of displaying such information in the wider population, or in different locations (for example fast food outlets, rather than just corner stores).

It is also difficult in such a study to definitely know how much the intervention is having a direct impact on people’s purchasing habits. In this study, the sample of interviews helped to inform this, which suggested that around a third had noticed the signs, and it had influenced the subsequent purchases of 40% of people.

The overall changes in beverage calories during and after the interventions was also fairly small (around 10-20kcal) so it is difficult to say whether or not this would have any meaningful effect on targeting overweight and obesity.

Though environmental interventions are likely to be of some effect in targeting the obesity epidemic, the overall change needs to be towards a healthier, balanced diet in general, combined with regular exercise, rather than change in just one specific area, such as whether or not you purchase an SSB.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on TwitterJoin the Healthy Evidence forum.

Links To The Headlines

Sugary drinks warning signs change habits of US teens. BBC News, October 17, 2014

Run FOUR miles to burn off just one bottle of coke: Scientists call for exercise data to be printed on packaging instead of calories. Mail Online, October 17 2014

Links To Science

Bleich SN, Barry CL, Gary-Webb TL, Herring  BJ. Reducing Sugar-Sweetened Beverage Consumption by Providing Caloric Information: How Black Adolescents Alter Their Purchases and Whether the Effects Persist. American Journal of Public Health. Published online October 16 2014

Categories: NHS Choices

Vegetative patients show awareness during scans

Fri, 17/10/2014 - 12:00

"Vegetative patients may be more conscious of the world than we think," The Independent reports. Electrodes have detected what has been described as "well-preserved" networks of brain activity in patients in a vegetative state.

A vegetative state is when a person is awake and may have some basic motor reflexes, but no signs of awareness. It is one of a group of conditions known as disorders of consciousness and often develops after a severe head injury.

This study performed electroencephalogram (EEG) examinations to study the electrical signals and connections in the brains of 32 people with disorders of consciousness, comparing them with 26 healthy adults.

The researchers demonstrated that the networks of electrical connections thought to support awareness are impaired in people with disorders of consciousness. They also found the quality of people's brain connections correlates with their level of awareness.

Most interestingly, they also found a small number of people in a vegetative state may have more conscious awareness than it seems.

Four people in this state were found to show some signs of "hidden awareness" – they demonstrated brain activity on functional MRI scans when asked to imagine playing tennis (in neurological circles, this is known as the tennis test).

When looking at the EEG results, the researchers found some of the brain connections that support consciousness in healthy adults were also well preserved in these people.

The researchers suggest these results may help improve clinical assessments in the future, as well as help identify people who may still have some level of conscious awareness, despite not being able to demonstrate this.

 

Where did the story come from?

The study was carried out by researchers from the University of Cambridge, the University of California, the University of Western Ontario, and the Universidad Diego Portales, Chile.

Funding was provided by various sources, including the Wellcome Trust, the UK Medical Research Council, and the National Institute for Health Research.

It was published in the peer-reviewed journal, PLOS Computational Biology, which is open access, so the study is available to read online for free.

The Independent and BBC News reported the study accurately. However, while the sentiment of the Daily Express' headline, "Talking to vegetative state patients can help recovery", may be well intentioned, it does not have a strong foundation.

Although the study found a small number of people in a vegetative state did seem to have some conscious awareness, despite this not being apparent, it did not look at their brain activity in response to friends and family talking to them. And it certainly has not examined whether this may or may not help them recover.

 

What kind of research was this?

This was a case control study that looked at electrical signals coming from the brains of people with disorders of consciousness, and compared them with normal healthy controls.

There are three conditions that generally fall into what are termed disorders of consciousness, which usually occur after a severe brain injury.

A minimally conscious state is where the person has very little consciousness, but demonstrates some variable response or awareness of their surroundings.

A vegetative state is the middle condition, where the person has no environmental awareness at all, but they still demonstrate a sleep-wake cycle and reflexive responses (such as to pain or sound).

A person in a coma is unconscious, with no awareness at all, does not respond to their environment, and has no sleep-wake cycle and no normal reflex responses.

This study aimed to further understand the distinctive brain networks that characterise the different disorders of consciousness.

 

What did the research involve?

This study took bedside EEG recordings of the electrical signals coming from the brains of 32 people with disorders of consciousness, as well as 26 healthy controls.

They looked at the amplitude of oscillations and then looked at the structure of brain networks connected by these oscillations.

The researchers then compared the electrical patterns and connections between the people with disorders of consciousness and the healthy controls.

They also examined what signalling abnormalities are present in people with disorders of consciousness, to what extent these patterns are consistent across patients, and how the patterns correlate with the level of behavioural response present.

 

What were the basic results?

The results of this study are quite complex, reporting the intricate differences in brain networks and connectivity between people with disorders of consciousness and healthy controls.

In general, the researchers found distinct differences in people with disorders of consciousness compared with the healthy controls.

They also found the quality of signalling networks in people with disorders of consciousness correlated with the degree of behavioural response they demonstrated.

Of the people in a vegetative state – who by definition have no behavioural responses – four out of 13 were surprisingly found to demonstrate some signs of brain activity when asked to imagine playing tennis while having their brain scanned by functional MRI scan.

When looking at the EEGs of this small number of vegetative patients with some signs of "hidden awareness", the researchers found they had well-preserved signalling networks similar to those of healthy adults.

 

How did the researchers interpret the results?

The researchers concluded that their findings "inform current understanding of disorders of consciousness by highlighting the distinctive brain networks that characterise them".

They say tests in a minority of people in a vegetative state indicate signalling pathways that could support mental function and consciousness, although these people have profound behavioural impairment.

 

Conclusion

This study performed EEG examinations to study the electrical signals and connections in the brains of 32 people with disorders of consciousness, comparing them with 26 healthy adults.

The researchers demonstrated the network of electrical connections that support awareness, and how these connections are impaired in people with disorders of consciousness. They also found the quality of people's brain connections correlates with their level of awareness.

Of most interest, they found a small number of people in a vegetative state may have more conscious awareness than it seems.

A vegetative state is characterised by a person maintaining spontaneous reflexes, such as to pain or sound, and having a normal sleep-wake cycle, but they cannot demonstrate behavioural responses or conscious awareness of their surroundings.

But in this study, four people in this state were found to show some signs of hidden awareness – they demonstrated brain activity on a functional MRI scan when asked to imagine playing tennis.

When looking at their EEGs, the researchers found some of the brain connections that support consciousness in healthy adults were also well preserved in these people, too.

The researchers suggest the distinct brain network connections seen in people with disorders of consciousness that they have identified in this study may help improve clinical assessments in the future.

This information may also help identify people who may still have some level of conscious awareness, despite not being able to demonstrate this.

Further research building on these findings is awaited. Despite one newspaper's report to the contrary, the results of this study are not suddenly going to lead to new treatments for disorders of consciousness – at least in the short term. But learning more about the relationship between brain activities and levels of awareness is always valuable.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Vegetative patients may be more conscious of the world than we think. The Independent, October 16 2014

Vegetative patients show glimmers of consciousness. BBC News, 17 October 2014

Talking to vegetative state patients can help recovery. Daily Express, 16 October 2014

Links To Science

Chennu S, Finoia P, Kamau E, et al. Spectral Signatures of Reorganised Brain Networks in Disorders of Consciousness. PLOS Computational Biology. Published 16 October 2014

Categories: NHS Choices

Crash diets 'work best' claim misguided

Thu, 16/10/2014 - 12:00

“Crash diets DO work, claim experts,” the Mail Online reports.

It reports on an Australian study involving 200 obese adults who were randomly assigned to either a 12-week rapid weight loss programme on a very low-calorie diet or a 36-week gradual weight loss programme.

It found that 81% of people in the rapid weight loss group achieved the target weight loss (more than 12.5% of their bodyweight), compared to 50% of those in the gradual weight loss group.

Participants, from both groups, who lost more than 12.5% of their bodyweight were then placed on a weight maintenance diet for three years. However, 71% of the weight was regained in both groups after this three-year period.

So it would appear, whatever the weight loss regime used, that the real challenge is keeping off the weight in the long term.

The study may also not have captured the harmful effects that may be associated with rapid weight loss, such as loss of muscle mass or poor nutrition.

If carefully supervised, very low-calorie meal replacements may be suitable for some people with obesity, at least as an initial measure, but they are not a long-term solution.

The NHS Choices weight loss plan uses a combination of not just diet, but also exercise and lifestyle changes, to achieve sustainable and prolonged weight loss.

 

Where did the story come from?

The study was carried out by researchers from the University of Melbourne and La Trobe University, Australia. It was funded by the Australian National Health and Medical Research Council and the Sir Edward Dunlop Medical Research Foundation.

One of the authors of the study has a history of previous employment with Nestle’s Optifast. Optifast was used as the low-calorie food substitute for the rapid weight loss group. Though Nestle played no role in either the funding, design or analysis of the study.

The study was published in the peer-reviewed medical journal The Lancet Diabetes and Endocrinology.

The study was covered widely and not always accurately in the media. The message in The Daily Telegraph that “crash diets” are more effective than gradual weight loss is misleading. Though more people achieved the target weight loss in the rapid weight loss group initially, in the long-term maintenance phase of the trial, 71% of both groups regained the weight they had lost.

Encouraging all people to go on crash diets is inadvisable – it should be pointed out that in this study, participants were carefully supervised by professionals experienced in treating obesity.

Reassuringly, most sources included information regarding the potential risks of low-calorie diets such as kidney damage and lack of adequate nutrition.

 

What kind of research was this?

This was a randomised controlled trial (RCT), which aimed to compare the effect of rapid and gradual weight loss programmes on both the rate of weight loss and the rate of weight regain in obese people.

The authors say that guidelines recommend gradual weight loss for the treatment of obesity on the grounds that weight lost rapidly is more quickly regained. However, there is evidence to suggest that this is not necessarily the case.

This RCT took place in two phases: an initial phase where people followed a rapid weight loss or gradual weight loss programme, followed by a second phase where those who had achieved the target weight loss entered the same longer-term maintenance phase.

 

What did the research involve?

The two phase trial took place between 2008 and 2013. It included 200 obese adults who were otherwise healthy and aged between 18 and 70 years. In the first phase, 103 participants were randomly assigned to a 12-week rapid weight loss (RWL) programme on a very low-calorie diet (450-800 kcal per day), and 97 were assigned to a 36-week gradual weight loss (GWL) programme, which reduced energy intake by 400 to 500 kcal a day, in line with current dietary guidelines in Australia, where the study took place.

Those in the RWL group consumed a commercially available "very low energy" meal (Optifast) instead of the usual three meals a day, following the manufacturer’s recommendations. The aim for this group was 15% weight loss during the 12 weeks (about 1.5kg per week). In the GWL programme, participants used one to two of the commercial meal replacements with the aim of 15% weight loss over 36 weeks (about 0.5kg per week).

All participants received the meal replacements free, and were given similar material on dietary education.

Those who achieved 12.5% weight loss or more in the allocated timeframe were eligible to enter the second phase of the trial, which continued for 144 weeks. In this phase, participants were instructed to follow an individualised diet for weight loss maintenance, based on Australian guidelines. They had individual sessions with dieticians at weeks four and 12 and then every 12 weeks. Adherence to the diet was assessed and those regaining lost weight were advised to follow an energy reduced diet (400-500 kcal a day less).

Throughout the study all participants were instructed to take 30 minutes or more daily of mild to moderate intensity exercise. Physical activity was measured using a pedometer worn for seven consecutive days.

Total study duration was three years for the RWL group and 3.5 years for the GWL group.

The main outcome examined was the average weight loss maintained at week 144 of the trial, in the second phase. Participants were weighed after fasting overnight. Their waist and hips were measured and their body composition analysed. Other outcomes examined were blood levels of certain hormones associated with appetite (ghrelin and leptin), and participants’ subjective appetite.

In their analyses, they looked at only those who had completed the trial, and carried out intention to treat analysis (ITT), in which all participants are included in the results, whether or not they have dropped out.

 

What were the basic results?

In the first phase of the trial, more participants in the rapid weight loss group achieved the target weight loss and started phase two of the trial (76 people; 81%) compared to participants in the gradual weight loss group (51; 50%)

However, at the end of the weight maintenance phase, there was no difference between groups in the proportion who regained weight. Looking at only those who completed the study (43/51 in GWL and 61/76 in RWL), roughly equivalent proportions in each group had regained most of their lost weight: 71.2% of the gradual weight loss group (95% confidence interval [CI] 58.1 to 84.3), and 70.5% of the rapid weight loss (95% CI 57.8 to 83.2).

Intention-to-treat analysis showed similar results: gradual weight loss 76.3% regain (95% CI 65.2 to 87.4) vs rapid weight loss 76.3% regain (95% CI 65.8 to 86.8).

Looking at adverse effects, during the first phase of the trial one person in the rapid weight loss group developed acute cholecystitis (gallbladder inflammation) and had to have their gallbladder removed. This adverse effect was considered to be “probably related to the rapid weight loss programme”.

During the second phase of the trial, two people in the rapid weight loss group developed cancer (multiple myeloma and breast cancer), but these adverse effects were not considered to be related to the dietary intervention.

 

How did the researchers interpret the results?

The researchers say their findings show that the rate at which weight is lost does not affect the rate at which it is regained during the weight loss maintenance period. These findings, they say, are not consistent with current dietary guidelines, which recommend gradual rather than rapid weight loss. They also point out that RWL was more likely to lead to target weight loss and fewer drop outs.

They say it is possible that low-energy meals are easier to follow because fewer choices have to be made than for a diet consisting of regular foods. The limited carbohydrate intake of very low-calorie diets may induce ketosis (where the body uses fat for energy), which might promote feelings of fullness. Losing weight quickly may also motivate people to persist with their diet and achieve better results, they argue.

The authors say that long-term weight regain is probably caused by a rise in levels of the hormone ghrelin after a weight loss programme. Experts should now focus on the safety of appetite suppressants to help prevent weight regain, they say.

 

Conclusion

This study challenges the widely held view that losing weight gradually, as recommended in current guidelines, results in better long-term weight reduction and less weight regain compared to losing weight rapidly using a very low-calorie diet.

The study found that though initially more people in the rapid weight loss group achieved the target weight loss compared to the gradual weight loss group, when these participants then entered the longer-term maintenance phase where all followed individualised diets. Equivalent proportions in each group then regained weight.

The sad fact seems to be that whatever type of diet is followed, maintaining weight loss in the long term is the real challenge.

The study had some limitations. As the authors point out, the main weakness was its exclusion of people who smoked, had diabetes, took weight-altering drugs or were severely obese. Many people with obesity also have diabetes and are often smokers. This makes it difficult to know if the results are generalisable to the average person seeking medical assistance with weight loss.

It is also important to recognise that this study may not have captured the harmful effects that may be associated with rapid weight loss. This study did observe that one person in the rapid weight loss group developed acute gallbladder inflammation, and this was attributed to the weight loss programme being followed. Rapid weight loss can also result in greater loss of muscle mass, and a very low-calorie diet may be short of essential nutrients.

It is possible that for some obese adults, a carefully supervised very low-calorie diet may be a suitable option, at least as an initial measure, but they are not a long-term solution and do not solve the goal of long-term maintenance of a healthy weight.

The best way to achieve a healthy weight and maintain it in the long term is likely to involve a long-term commitment to a lifestyle change, involving a healthy, balanced diet with regular exercise in line with government recommendations.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Crash diets DO work, claim experts - but can still be dangerous as it is 'impossible' to gain all the nutrients the body needs. Mail Online, October 16 2014

Crash-dieting more effective than gradual weight loss, study suggests. The Daily Telegraph, October 16 2014

Crash diets might not be so bad in beating fat after all, suggests new study. The Independent, October 16 2014

Crash dieting IS the best way to loose weight, say experts. Daily Express, October 16 2014

Links To Science

Purcell K, Sumithran P, Prendergast LA, et al. The effect of rate of weight loss on long-term weight management: a randomised controlled trial. The Lancet Diabetes & Endocrinology. Published online October 16 2014

Categories: NHS Choices

New way to distinguish between ovarian tumours

Thu, 16/10/2014 - 11:29

"A new test can help doctors identify ovarian cancer more accurately and cut down on instances of unnecessary surgery," BBC News reports.

The BBC accurately reflects the findings of researchers who developed new tests for ovarian cancer. These tests use clinical and ultrasound findings to assess whether tumours are benign or malignant and, if they were malignant, the likely stage of the cancer (how far the cancer has spread).

More accurate testing could lead to women with ovarian cancer getting the most appropriate treatment. In younger women, it may also help ensure, where possible, their fertility is preserved in some cases.

The series of tests used by the researchers are based on a "prediction model" developed using information from more than 3,000 women who had a "mass" seen on their ovaries at ultrasound. These masses were then surgically removed and examined in the laboratory.

This model was able to distinguish well between benign and malignant tumours, as well as assessing the stage of any spread.

Although the researchers suggest the predictive model (called ADNEX) could be improved and used as a second-stage test to distinguish between different types of ovarian tumours, it is not a screening test. Screening for ovarian cancer does not presently take place in the UK.

 

Where did the story come from?

The study was carried out by researchers from the University of Leuven in Belgium in collaboration with researchers from across Europe and the International Ovarian Tumour Analysis group.

It was funded by the Flemish government, the UK National Institute for Health Research, the Swedish Medical Research Council, funds administered by Malmö University Hospital and Skåne University Hospital, the Malmö General Hospital Foundation for Fighting Against Cancer, and two Swedish government grants.

The study was published in the peer-reviewed British Medical Journal (BMJ). This article is open access, meaning it can be downloaded and read for free.

The BBC reported the story well, emphasising that, in its present state, the research could help ensure women get the appropriate treatment, rather than providing the basis for a general screening programme.

 

What kind of research was this?

This was a cohort study of women with at least one ovarian mass (tumour) that needed to be surgically removed. The researchers wanted to find a way to predict risk, using ultrasound features and other patient characteristics to help distinguish between different types and stages of ovarian tumour (including benign and malignant) prior to surgery.

Knowing the likely stage and grade of individual cases of ovarian cancers would allow teams to optimise treatments, which should lead to improved outcomes. Also, in younger women, it may offer the opportunity to preserve fertility.

If a cancer is at a very early stage, it can be possible to treat it by removing the ovaries but leaving the womb intact. The woman would then still have the option to conceive through IVF with donor eggs or eggs removed prior to surgery.

 

What did the research involve?

The researchers studied ultrasound and clinical data from 3,506 women with an ovarian mass who had an ultrasound before the mass was removed by surgery. The mass was examined in the laboratory and classified into one of five tumour types.

The researchers used all of this data to create a "prediction model", which they called Assessment of Different Neoplasias in the Adnexa (ADNEX), to help distinguish between:

  • benign tumours (not cancerous)
  • borderline tumours (tumours that normally grow slowly and have low malignant potential)
  • stage I invasive tumours (cancer is only in the ovaries)
  • stage II to IV invasive tumours (the cancer has spread to other organs)
  • secondary metastatic ovarian tumours (where the cancer didn't start in the ovaries, but has spread to them from somewhere else in the body)

The researchers tested their prediction model to see whether it could distinguish between these different types of tumours on a further 2,403 women. They used their findings from these women to update their prediction model.

 

What were the basic results?

The ADNEX prediction model contained three clinical and six ultrasound predictors:

  • age
  • blood levels of cancer antigen-125 (a tumour marker that can be raised in ovarian cancer)
  • the type of centre the woman was being treated at (oncology centre or other hospital)
  • maximum diameter of the mass proportion of solid tissue
  • more than 10 cyst locules (making the mass look like a cluster of grapes)
  • number of papillary projections (where the wall of the mass projects into the mass itself)
  • acoustic shadows (loss of sound echo behind a sound-absorbing structure)
  • ascites (presence of abnormal free fluid in the abdomen)

The researchers looked at how well the prediction tool was able to distinguish between the different types of tumour.

The tool was found to be able to distinguish between benign and malignant tumours. The area under the curve (AUC) for distinguishing between all benign and malignant tumours was 0.94 (AUC can range from 0 to 1, with 1 being a perfect test, with no false positives or false negatives). An AUC of 0.94 shows good distinguishing power between benign and malignant tumours.

When looking at the ability to distinguish between benign and different stages of cancerous tumour, the AUC ranged from 0.85 for benign versus borderline, to 0.99 for benign versus stage II to IV ovarian cancer.

The tool had a variable level of accuracy distinguishing between different types and states of cancer. For example, the AUCs ranged from 0.71 for stage I versus secondary metastatic, and 0.75 for borderline versus stage I, to 0.95 for borderline versus stage II to IV.

The performance of a test depends on the cut-off you select. When the cut-off was set so women tested positive for a malignant tumour if the ADNEX said they had a 10% risk or more of the tumour being malignant, the tool had a sensitivity of around 96.5%, which is the proportion of women with a malignant tumour accurately detected as malignant. It also had a specificity of 71.3%, which is the proportion of those with a benign tumour accurately detected as benign.

This means that at this cut-off the test has a very low "false negative" rate, but quite a high "false positive" rate. This is important because it means that while the test could be very useful in detecting potentially harmful cancers, around 30% of women with benign tumours were also given a positive test result.

 

How did the researchers interpret the results?

The researchers concluded that, "The ADNEX model discriminates well between benign and malignant tumours and offers fair to excellent discrimination between four types of ovarian malignancy.

"The use of ADNEX has the potential to improve triage and management decisions, and so reduce morbidity and mortality associated with adnexal [ovarian] pathology."

 

Conclusion

This study describes a new way of distinguishing between benign and malignant ovarian tumours, and for distinguishing between different stages of malignant tumours.

The reseachers found their prediction model was able to discriminate well between benign and malignant tumours overall. But it showed more variable accuracy for distinguishing between different stages of ovarian cancer – for example, between borderline, stage I and stage II to IV ovarian cancers and secondary metastatic tumours.

As the researchers point out, a potential limitation of their study is they were only able to study tumours from women who were about to undergo surgery to remove the tumour.

They were unable to study women with ovarian masses who were deemed not to require, or were not suitable for, surgery and who underwent "expectant management" (watching and waiting). They say information on women who are managed conservatively started being collected in 2013.

The researchers hope the ADNEX tool will be able to aid decisions about treatment of ovarian cancer and improve outcomes.

It should be noted ADNEX is not a screening test and screening for ovarian cancer does not presently take place in the UK.

While the initial symptoms of ovarian cancer aren't very specific (symptoms could have a wide range of potential causes), you should contact your GP for advice if you have persistent bloating, difficulty eating, and pain in the pelvis or abdomen.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

New test 'helps identify best ovarian cancer treatment'. BBC News, October 16 2014

Links To Science

Van Calster B, Van Hoorde K, Valentin L, et al. Evaluating the risk of ovarian cancer before surgery using the ADNEX model to differentiate between benign, borderline, early and advanced stage invasive, and secondary metastatic tumours: prospective multicentre diagnostic study. BMJ. Published online October 15 2014

Categories: NHS Choices

Stem cells used to improve low vision

Wed, 15/10/2014 - 13:00

"Embryonic stem cells transplanted into eyes of blind restore sight," The Daily Telegraph reports, covering a study where human stem cells were transplanted into the eyes of people with visual impairment. This led to a significant improvement in their vision.

This new research involved nine women with age-related macular degeneration and nine people with a rare condition called Stargardt's macular dystrophy, both of which cause progressive damage to the retina. Macular degeneration is the leading cause of visual impairment in the UK, and until now there has been no treatment.

The participants had retina cells derived from human embryonic stem cells transplanted into the space behind the retina in the eye with the worst vision. Before surgery, they had severe visual loss. After 12 months, vision in the treated eye improved significantly.

Some papers reported how some participants were able to read a watch or use a computer after receiving treatment, though this is not mentioned in the actual study. What is described is a marked improvement in Snellen test scores, where you read a chart of letters that get progressively smaller.

Contrary to headlines, there were some side effects, but these all resolved. And over an average of 22 months' follow-up, there were no signs of transplant rejection or major complications.

Further larger studies will doubtless now be underway to determine the optimal dosage and conditions for success.

 

Where did the story come from?

The study was carried out by researchers from the University of California, Wills Eye Hospital and Thomas Jefferson University, the University of Miami, the Massachusetts Eye and Ear Infirmary and Harvard Medical School, Advanced Cell Technology, and the Medical University of South Carolina.

It was funded by Advanced Cell Technology, a biotechnology company that develops and commercialises stem cell therapies.

Researchers from the company were involved in the study design, data collection, analysis, interpretation and writing the report.

This means there is potential for bias of the results. However, the other authors had full access to all of the data and responsibility for arranging publication.

The study was published in the peer-reviewed medical journal, The Lancet.

In general, the media reported on the study accurately, and The Guardian provided expert quotes about the positive effect the improvement in sight had on some of the participants.

Contrary to The Independent's headline, however, a number of side effects were experienced as a result of the surgical procedure and immunosuppression.

Claims the participants were blind are also not entirely technically correct, as they had some degree of vision. Blindness – complete loss of vision – is actually uncommon. Most people with visual impairment have some limited degree of low vision.

 

What kind of research was this?

This research described two phase one/two trials that aimed to test the long-term safety and effectiveness of transplanting retinal pigment epithelium cells derived from human embryonic stem cells into the eye.

Phase one trials are the first type of study for new treatments conducted in humans. They aim to test the safety and suitability of the treatment for humans.

Phase two trials look at the effectiveness of the treatment and help determine the optimal dose. They also further assess any side effects. These trials were a combination of the two.

 

What did the research involve?

Nine women with age-related macular degeneration (median age 77, range 70 to 88) and nine people with Stargardt's macular dystrophy (median age 50, range 20 to 71) were recruited to the study from four US hospitals.

The researchers took human embryonic stem cells, which are able to become any tissue type, and developed them into retinal pigment epithelium cells. These cells were injected just behind the retina of the eye with the worst vision.

Three different doses were tested: 50,000 cells, 100,000 cells or 150,000 cells. Each dose was given to three people with age-related macular degeneration and three people with Stargardt's macular dystrophy.

All of the participants were given drugs to suppress their immune system (immunosuppressants) from one week before the transplant to 12 weeks afterwards to reduce the risk of transplant rejection.

The groups were followed up with numerous eye and physical examinations over a median period of 22 months (four people for less than 12 months, 12 people for 12 to 36 months, and two people for more than 36 months).

 

What were the basic results?

Before treatment, the best visual ability ranged from 20/200 (severe visual loss) to near blindness. (The 20/200 score means they could only read words from 20 metres away that a person with healthy vision would be able to read from 200 metres away). 

In the age-related macular degeneration group, after six months:

  • four people could see at least 15 more letters in the treated eye during the Snellen test (equivalent to three lines on the standard visual chart)
  • two people could see at least 11 to 14 more letters
  • three people remained stable or could see up to 10 more letters

After 12 months:

  • three people could see at least 15 more letters in the treated eye
  • one person could see at least 13 more letters
  • three people remained stable or could see up to 10 more letters
  • two people did not have a 12-month assessment

In the Stargardt's macular dystrophy group, after six months:

  • three people could see at least 15 more letters in the treated eye
  • four people remained stable or could see up to 10 more letters
  • one person had a deterioration of 11 letters
  • one person did not have a six-month assessment

After 12 months:

  • three people could see at least 15 more letters in the treated eye
  • three people remained stable or could see up to 10 more letters
  • one person had a deterioration of more than 10 letters
  • two people did not have a 12-month assessment

The higher dose of cells – 150,000 – gave better results in the age-related macular degeneration group. A lower dose of 50,000 gave the best results in the Stargardt's macular dystrophy group.

Participants also had, on average, improved quality of life, as measured by a questionnaire.

Nobody had acute transplant rejection, abnormal excess growth of the transplanted stem cells, or tumour formation. In addition, they did not experience retinal detachment or changes in the blood vessels of the retina.

There were some side effects from the treatment, however, including:

  • retinal cells grew in front of the retina in three people, but did not cause any problems
  • four eyes developed cataracts, which were treated with surgery – one with age-related macular degeneration, and three with Stargardt's macular dystrophy
  • one person had severe inflammation of the fluid compartment inside the eye after surgery and an infection with Staphylococcus epidermidis – this took two months to resolve and sight returned to pre-operation level after three months
  • another person also had inflammation of the fluid compartment three weeks after the transplant, which resolved slowly over six months
  • several systemic adverse events were reported as a result of immunosuppression

 

How did the researchers interpret the results?

The researchers concluded that they "have shown the medium-term to long-term safety, graft survival, and possible biological activity of pluripotent stem cell progeny in individuals with atrophic age-related macular degeneration and Stargardt's macular dystrophy.

They go on to say that, "Our results suggest that hESC-derived cells [human embryonic stem cells] could provide a potentially safe new source of cells for the treatment of a variety of unmet medical conditions caused by tissue loss or dysfunction.

"The goal should be to treat patients early in the disease, potentially increasing the likelihood of photoreceptor and central visual maintenance or rescue in amenable retinal disorders."

 

Conclusion

These phase one/two studies have shown human embryonic stem cells can be developed into retinal cells in the laboratory and successfully transplanted into the eye, causing clinically significant visual improvements.

The technique does come with the usual potential surgical complications, but other major side effects were not found.

Limitations of the study include the small size, but this is normal in early trials whose primary aim is to determine safety.

Larger studies will be required to determine the optimal dose and the most appropriate candidates for the technique, as it was detrimental in one person and did not improve – or gave minimal improvement to – six other people.

There will also be ongoing ethical considerations for the technique, which currently uses cells left over from in vitro fertilisation (IVF).

Overall, these studies show a promising treatment for two of the commonest causes of visual impairment in the developed world, though it will take a few more years of trials to optimise the technique.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Embryonic stem cells transplanted into eyes of blind restore sight. The Daily Telegraph, October 15 2014

Stem cell therapy success in treatment of sight loss from macular degeneration. The Guardian, October 15 2014

Stem cell trial cures blindness for many patients – with no side effects. The Independent, October 15 2014

Links To Science

Schwartz SD, Regillo CD, Lam BL, et al. Human embryonic stem cell-derived retinal pigment epithelium in patients with age-related macular degeneration and Stargardt's macular dystrophy: follow-up of two open-label phase 1/2 studies (PDF, 2Mb). The Lancet. Published online October 15 2014

Categories: NHS Choices

Warnings issued over energy drinks

Wed, 15/10/2014 - 12:00

“Energy drinks could cause public health problems, says WHO study,” The Guardian reports. A new review discusses the potential harms of these drinks, especially when they are mixed with alcohol.

Energy drinks, such as Red Bull and Monster, contain high levels of caffeine, which is a stimulant. They have become increasingly popular over the last 20 years, especially with young people, with many clubbers mixing them with alcohol.

The Guardian reports on a new review by the World Health Organization (WHO), which reviewed the literature on the associated health risks and policies related to energy drinks. The review was prompted by concerns raised both by the scientific community and among the general public about the health effects of these drinks. It should be noted that although the researchers were from WHO, the review's conclusions do not necessarily represent the decisions or stated policy of WHO.

The researchers described a number of potential health risks, mainly associated with the high caffeine content of the drinks, as well as the risks of combining them with alcohol. They also found that policy regarding energy drinks is limited and call for more long-term research and policy action, to minimise the risk of harm from heavy and long-term energy drink consumption.

 

What is the basis for these reports?

Researchers from the World Health Organization (WHO) have written a narrative review of studies on the health risks associated with energy drink consumption and policies related to energy drinks.

The review has been published in the peer-reviewed health journal Frontiers in Public Health on an open-access basis, so it is free to read online.

As this is a narrative rather than a systematic review, we don’t know if all relevant literature has been included or whether other researchers reviewing the same topic would reach the same conclusions.

With a narrative review there is always the possibility that the evidence has been “cherry-picked” – that is, evidence that supports the researchers’ arguments is included, but contrasting evidence is ignored. However, we would be surprised if this was the case here, as WHO researchers have a well-deserved reputation for impartiality and integrity.

 

What are energy drinks?

Although there is no standard definition of an “energy drink”, it is taken to mean a non-alcoholic drink that contains caffeine, taurine (an amino acid) and vitamins, in addition to other ingredients.

They were originally introduced in Japan during the 1960s and became increasingly popular in Europe during the 1980s and 90s, possibly due to the rise of rave culture.

It is now commonplace, especially among young people, to mix energy drinks with alcoholic spirits. Many pubs and clubs will sell jugs or “goldfish bowls” of Red Bull and vodka.

Energy drinks are marketed for their perceived or actual benefits as a stimulant, for improving performance and increasing energy. Companies often have sponsorship deals with extreme sport franchises, presumably to sell the message that energy drinks are “edgy and energetic”.

They are now big business. In the EU, it is estimated that 30% of adults and 68% of adolescents consume energy drinks, with global sales estimated to be around $12 billion in 2012. 

 

What are the risks associated with energy drink consumption?

The researchers state that the health risks associated with energy drink consumption are primarily related to their caffeine content.

Potential risks associated with energy drink consumption include:

  • caffeine overdose (which can lead to a number of symptoms, including palpitations, high blood pressure, nausea and vomiting, convulsions and, in some cases, even death)
  • type 2 diabetes – as high consumption of caffeine reduces insulin sensitivity
  • late miscarriages, low birthweight and stillbirths in pregnant women
  • neurological and cardiovascular system effects in children and adolescents
  • sensation-seeking behaviour
  • use and dependence on other harmful substances
  • poor dental health
  • somewhat ironically, given their association with sportiness, obesity

Energy drinks also contain a variety of other ingredients, such as guarana, and the effect of long-term regular consumption of the combination of the substances in energy drinks is unknown.

The increasing practice of mixing energy drinks with alcohol also carries risks. The researchers state that the consumption of high amounts of caffeine (as found in energy drinks) reduces drowsiness without diminishing the effects of alcohol, resulting in “wide awake drunkenness.” Therefore, there is the risk that people will engage in risky and dangerous behaviour, such as violence or unprotected sex, as the mix of alcohol and caffeine can lead to a loss of inhibition.

 

What policies exist to regulate the labelling, distribution and sale of energy drinks?

Energy drinks can be sold in all EU member states. Since 2004, energy drinks that contain at least 150mg/l of caffeine have enforced additional caffeine labelling under European regulations. From 2014, these will be labelled with, “High caffeine content. Not recommended for children or pregnant or breastfeeding women,” and the caffeine content will also be expressed in mg/100ml.

Some countries have additional regulations – in Sweden, for example, sales of some products are restricted to pharmacies, and sales to children under 15 are banned.

 

What policies do the researchers suggest?

The researchers suggest the introduction of the following policies:

  • an evidence-based, upper limit for the amount of caffeine allowed in a single serving of any drink
  • a restriction in sales to children and adolescents
  • the education of healthcare providers to recognise caffeine intoxication, withdrawal and dependence
  • regulation of the marketing of energy drinks; for example, a ban on adverts that are obviously designed to target young people or suggest an association between energy drinks and sporting prowess

 

What future work do the researchers suggest?

The researchers state that more research is required to discover the effects of long-term energy drink consumption, particularly among children and young adults, and the best ways to restrict their usage.

 

What are the researchers' conclusions?

The researchers conclude that: “The health risks associated with energy drink consumption are primarily related to their caffeine content, but more research is needed that evaluates the long-term effects of consuming common energy drink ingredients. The evidence indicating adverse health effects due to the consumption of energy drinks with alcohol is growing. The risks of heavy consumption of energy drinks among young people have largely gone unaddressed and are poised to become a significant public health problem in the future.”

What's important to realise is that energy drinks contain caffeine, often in large quantities. This could pose a risk to your health if consumed in high quantities and/or mixed with alcohol.

Analysis by Bazian. Edited by NHS ChoicesFollow Behind the Headlines on TwitterJoin the Healthy Evidence forum.

Links To The Headlines

Energy drinks could cause public health problems, says WHO study. The Guardian, October 14 2014

Poorly regulated energy drinks could be harming children, WHO warns. The Independent, October 14 2014

Sales of sugar and caffeine laden energy drinks should be restricted as they 'pose a danger' to children. Daily Mail, October 15 2014

Restrict energy drink sales, say scientists. The Times, October 15 2014

Links To Science

Breda JJ, Whiting SH,  Encarnação R, et al. Energy drink consumption in Europe: a review of the risks, adverse health effects, and policy options to respond. Frontiers in Public Health. Published online October 14 2014

Categories: NHS Choices

Broccoli could 'hold the key' for treating autism

Tue, 14/10/2014 - 12:00

"Broccoli chemical may improve autism symptoms," The Daily Telegraph reports. A small study suggests sulforaphane, a chemical that gives broccoli its distinctive taste, may help improve some of the symptoms of autism spectrum disorder (ASD).

The study found the symptoms of ASD improved in two-thirds of adolescent and young men who took a sulforaphane supplement.

In the randomised controlled trial, 26 men with moderate to severe ASD took sulforaphane, and nine took a placebo, for 18 weeks.

Improvements were seen in the majority of people taking sulforaphane in terms of irritability, lethargy, stereotypy, hyperactivity, awareness, communication, motivation and mannerisms.

The study was limited by the small number of participants, and the results may not be generalisable to all people with ASD, as it was conducted on a group of young white males.

Still, the results are both intriguing and encouraging, as there is currently no effective drug-based treatment for improving ASD symptoms.

Larger studies on more diverse groups of people will be required to assess the benefits and potential side effects of sulforaphane, which could be recommended for people with ASD.

 

Where did the story come from?

The study was carried out by researchers from the Massachusetts General Hospital for Children, the University of Massachusetts and The John Hopkins University School of Medicine.

It was funded by the Nancy Lurie Marks Family Foundation, the Hussman Foundation, the Lewis B and Dorothy Cullman Foundation, the Agnes Gund Foundation, the N of One Foundation and the Brassica Foundation for Chemoprotection Research.

Three of the authors are listed as inventors on a Johns Hopkins University US patent application, with two of these authors having renounced any potential financial benefits from these patents.

The use of broccoli sprouts and seeds has been licensed to a company called Brassica Protection Products LLC, and the son of one of the authors is the company's chief executive officer. These potential conflicts of interest were made clear in the study.

The study was published in the peer-reviewed medical journal Proceedings of the National Academy of Sciences of the United States of America (PNAS). It has been published on an open access basis, so is free to read online.

The UK media generally reported the story accurately and pointed out the small number of participants, which limited the study.

 

What kind of research was this?

This was a double-blind randomised controlled trial looking at the effects of the chemical sulforaphane on symptoms of ASD. Sulforaphane is found in broccoli, Brussels sprouts, cauliflower and cabbage.

It is believed to increase the activity of genes that help cells protect themselves from damage caused by inflammation, oxidative stress or radiation.

The researchers say some of these biochemical problems are found in people with ASD, which is why they wanted to test the effect of this chemical. Sulforphane is also being evaluated for a number of other conditions.

As it was a randomised controlled trial, it has the potential to prove cause and effect, as all other confounders should be balanced between the groups.

However, randomisation may be less effective if there are only a small number of participants, as was the case in this study, as it is more likely that any results have been influenced by chance.

The researchers reported that the groups were well matched for the characteristics they assessed, but there may be unmeasured characteristics that differed. Small studies such as this tend to be carried out to get an idea of whether something looks promising, and then more people can be recruited for larger-scale studies.

 

What did the research involve?

The researchers recruited 44 males aged 13 to 27 diagnosed with moderate to severe ASD. They were randomly assigned to take either sulforaphane or placebo by mouth for 18 weeks.

As this was a double-blind study, neither the doctors nor the participants knew which drug they were taking.

The dose of sulforaphane was 50 to 150 micromoles per day, depending on the participants' body weight. The sulforphane in this study was extracted from broccoli sprouts.

It was unclear exactly how many vegetables you would have to eat to achieve the same dose of sulphorphane used in this study.

Behaviour was assessed before the treatment, at weeks 4, 10 and 18 during the treatment, and 4 weeks after the treatment had finished.

Parents or caregivers rated the participants' behaviour using standard scales called the Aberrant Behaviour Checklist (ABC) and the Social Responsiveness Scale (SRS), while the doctors completed the Clinical Global Impression Improvement (CGI-I) scale.

 

What were the basic results?

On average, the 26 people taking sulforaphane showed statistically significant improvement at weeks 4, 10 and 18, compared with 14 people taking placebo for:

  • irritability, lethargy, stereotypy (repetitive movements) and hyperactivity according to the ABC scale
  • awareness, communication, motivation and mannerism according to the SRS scale

At 18 weeks, there was "much" or "very much" improvement in the CGI-I scale scores for:

  • social interaction in 12 people (46%) on sulforaphane compared with none (0%) taking placebo
  • aberrant behaviour in 14 people (54%) on sulforaphane compared with 1 person (9%) on placebo
  • verbal communication in 11 people (42%) on sulforaphane compared with none (0%) taking placebo

The improvements were no longer present when participants had stopped taking the sulforaphane.

Four people did not attend the first follow-up visit: this comprised three who had been allocated to take sulforaphane and one who had been given the placebo.

People taking sulforaphane gained an average of 4.31 pounds over the 18-week period, compared with 0.31 pounds in the placebo group.

One participant on sulforaphane had a seizure after taking it for three weeks, with no previous history of seizures. Another participant had a history of epilepsy and was taking medication, but he had a seizure three weeks after stopping sulforaphane.

 

How did the researchers interpret the results?

The researchers concluded that daily sulforaphane caused "substantial" improvements in behaviour, social interaction and verbal communication.

They recognise the effects were not seen in all participants taking sulforaphane, and acknowledge that further larger multi-centre studies need to be conducted to obtain conclusive results.

 

Conclusion

This randomised controlled study has found sulforaphane – a chemical found in broccoli, Brussels sprouts, cabbage and cauliflower – may have beneficial effects for some people with ASD.

The study did not test the effect of eating these vegetables themselves – instead, it tested an extract made from broccoli sprouts. It was unclear exactly how many vegetables you would have to eat to achieve the same dose of sulforaphane used in this study.

The main limitation of the study was the small number of selected participants. All participants were male, aged between 13 and 27, predominantly white and had moderate to severe ASD. Therefore, it is unclear whether a similar effect would be seen in people with higher-functioning autistic symptoms, such as Asperger's syndrome.

In addition, 80% of them were reported to have symptom improvement when they had a fever; this is usually seen in 35% of people with ASD. This means the results may not be generalisable to all people with ASD.

Larger studies on more diverse groups of people will be required to further evaluate the positive effects and potential side effects of sulforaphane before it could be recommended for more widespread use in people with ASD.

Broccoli is a healthy food option as it contains a wide range of vitamins and nutrients (though claims it is a superfood are arguably overhyped), so encouraging your child to eat it certainly won't do any harm.

However, as autism expert Dr Rosa Hoekstra says in the Mail Online: "As things stand, parents of a child with autism should not feel guilty if their child refuses to eat broccoli."

Analysis by Bazian. Edited by NHS ChoicesFollow Behind the Headlines on TwitterJoin the Healthy Evidence forum.

Links To The Headlines

Broccoli chemical may improve autism symptoms. The Daily Telegraph, October 13 2014

Chemical contained in broccoli extract could offer help for autism symptoms. The Independent, October 14 2014

Could symptoms of autism be improved by eating broccoli? Chemical which gives veg its bitter taste 'helps autistic teens become calmer and more sociable'. Mail Online, October 14 2014

Links To Science

Singh K, Connors SL, Macklin EA, et al. Sulforaphane treatment of autism spectrum disorder (PDF, 1.3Mb). PNAS. Published online October 13 2014

Categories: NHS Choices

Broccoli could 'hold the key' for treating autism

Tue, 14/10/2014 - 12:00

"Broccoli chemical may improve autism symptoms," The Daily Telegraph reports. A small study suggests sulforaphane, a chemical that gives broccoli its distinctive taste, may help improve some of the symptoms of autism spectrum disorder (ASD).

The study found the symptoms of ASD improved in two-thirds of adolescent and young men who took a sulforaphane supplement.

In the randomised controlled trial, 26 men with moderate to severe ASD took sulforaphane, and nine took a placebo, for 18 weeks.

Improvements were seen in the majority of people taking sulforaphane in terms of irritability, lethargy, stereotypy, hyperactivity, awareness, communication, motivation and mannerisms.

The study was limited by the small number of participants, and the results may not be generalisable to all people with ASD, as it was conducted on a group of young white males.

Still, the results are both intriguing and encouraging, as there is currently no effective drug-based treatment for improving ASD symptoms.

Larger studies on more diverse groups of people will be required to assess the benefits and potential side effects of sulforaphane, which could be recommended for people with ASD.

 

Where did the story come from?

The study was carried out by researchers from the Massachusetts General Hospital for Children, the University of Massachusetts and The John Hopkins University School of Medicine.

It was funded by the Nancy Lurie Marks Family Foundation, the Hussman Foundation, the Lewis B and Dorothy Cullman Foundation, the Agnes Gund Foundation, the N of One Foundation and the Brassica Foundation for Chemoprotection Research.

Three of the authors are listed as inventors on a Johns Hopkins University US patent application, with two of these authors having renounced any potential financial benefits from these patents.

The use of broccoli sprouts and seeds has been licensed to a company called Brassica Protection Products LLC, and the son of one of the authors is the company's chief executive officer. These potential conflicts of interest were made clear in the study.

The study was published in the peer-reviewed medical journal Proceedings of the National Academy of Sciences of the United States of America (PNAS). It has been published on an open access basis, so is free to read online.

The UK media generally reported the story accurately and pointed out the small number of participants, which limited the study.

 

What kind of research was this?

This was a double-blind randomised controlled trial looking at the effects of the chemical sulforaphane on symptoms of ASD. Sulforaphane is found in broccoli, Brussels sprouts, cauliflower and cabbage.

It is believed to increase the activity of genes that help cells protect themselves from damage caused by inflammation, oxidative stress or radiation.

The researchers say some of these biochemical problems are found in people with ASD, which is why they wanted to test the effect of this chemical. Sulforphane is also being evaluated for a number of other conditions.

As it was a randomised controlled trial, it has the potential to prove cause and effect, as all other confounders should be balanced between the groups.

However, randomisation may be less effective if there are only a small number of participants, as was the case in this study, as it is more likely that any results have been influenced by chance.

The researchers reported that the groups were well matched for the characteristics they assessed, but there may be unmeasured characteristics that differed. Small studies such as this tend to be carried out to get an idea of whether something looks promising, and then more people can be recruited for larger-scale studies.

 

What did the research involve?

The researchers recruited 44 males aged 13 to 27 diagnosed with moderate to severe ASD. They were randomly assigned to take either sulforaphane or placebo by mouth for 18 weeks.

As this was a double-blind study, neither the doctors nor the participants knew which drug they were taking.

The dose of sulforaphane was 50 to 150 micromoles per day, depending on the participants' body weight. The sulforphane in this study was extracted from broccoli sprouts.

It was unclear exactly how many vegetables you would have to eat to achieve the same dose of sulphorphane used in this study.

Behaviour was assessed before the treatment, at weeks 4, 10 and 18 during the treatment, and 4 weeks after the treatment had finished.

Parents or caregivers rated the participants' behaviour using standard scales called the Aberrant Behaviour Checklist (ABC) and the Social Responsiveness Scale (SRS), while the doctors completed the Clinical Global Impression Improvement (CGI-I) scale.

 

What were the basic results?

On average, the 26 people taking sulforaphane showed statistically significant improvement at weeks 4, 10 and 18, compared with 14 people taking placebo for:

  • irritability, lethargy, stereotypy (repetitive movements) and hyperactivity according to the ABC scale
  • awareness, communication, motivation and mannerism according to the SRS scale

At 18 weeks, there was "much" or "very much" improvement in the CGI-I scale scores for:

  • social interaction in 12 people (46%) on sulforaphane compared with none (0%) taking placebo
  • aberrant behaviour in 14 people (54%) on sulforaphane compared with 1 person (9%) on placebo
  • verbal communication in 11 people (42%) on sulforaphane compared with none (0%) taking placebo

The improvements were no longer present when participants had stopped taking the sulforaphane.

Four people did not attend the first follow-up visit: this comprised three who had been allocated to take sulforaphane and one who had been given the placebo.

People taking sulforaphane gained an average of 4.31 pounds over the 18-week period, compared with 0.31 pounds in the placebo group.

One participant on sulforaphane had a seizure after taking it for three weeks, with no previous history of seizures. Another participant had a history of epilepsy and was taking medication, but he had a seizure three weeks after stopping sulforaphane.

 

How did the researchers interpret the results?

The researchers concluded that daily sulforaphane caused "substantial" improvements in behaviour, social interaction and verbal communication.

They recognise the effects were not seen in all participants taking sulforaphane, and acknowledge that further larger multi-centre studies need to be conducted to obtain conclusive results.

 

Conclusion

This randomised controlled study has found sulforaphane – a chemical found in broccoli, Brussels sprouts, cabbage and cauliflower – may have beneficial effects for some people with ASD.

The study did not test the effect of eating these vegetables themselves – instead, it tested an extract made from broccoli sprouts. It was unclear exactly how many vegetables you would have to eat to achieve the same dose of sulforaphane used in this study.

The main limitation of the study was the small number of selected participants. All participants were male, aged between 13 and 27, predominantly white and had moderate to severe ASD. Therefore, it is unclear whether a similar effect would be seen in people with higher-functioning autistic symptoms, such as Asperger's syndrome.

In addition, 80% of them were reported to have symptom improvement when they had a fever; this is usually seen in 35% of people with ASD. This means the results may not be generalisable to all people with ASD.

Larger studies on more diverse groups of people will be required to further evaluate the positive effects and potential side effects of sulforaphane before it could be recommended for more widespread use in people with ASD.

Broccoli is a healthy food option as it contains a wide range of vitamins and nutrients (though claims it is a superfood are arguably overhyped), so encouraging your child to eat it certainly won't do any harm.

However, as autism expert Dr Rosa Hoekstra says in the Mail Online: "As things stand, parents of a child with autism should not feel guilty if their child refuses to eat broccoli."

Analysis by Bazian. Edited by NHS ChoicesFollow Behind the Headlines on TwitterJoin the Healthy Evidence forum.

Links To The Headlines

Broccoli chemical may improve autism symptoms. The Daily Telegraph, October 13 2014

Chemical contained in broccoli extract could offer help for autism symptoms. The Independent, October 14 2014

Could symptoms of autism be improved by eating broccoli? Chemical which gives veg its bitter taste 'helps autistic teens become calmer and more sociable'. Mail Online, October 14 2014

Links To Science

Singh K, Connors SL, Macklin EA, et al. Sulforaphane treatment of autism spectrum disorder (PDF, 1.3Mb). PNAS. Published online October 13 2014

Categories: NHS Choices

Concerns raised about late diagnosis of lung cancer

Tue, 14/10/2014 - 12:00

"Doctors in Britain are 'missing opportunities' to spot lung cancer at an early stage," BBC News reports. A study found around a third of people with the condition die within 90 days of their initial diagnosis.

The study looked at the medical records of more than 20,000 adults who had been diagnosed with lung cancer in the UK between 2000 and 2013.

They found people were more likely to die early if they were male, over the age of 80, currently smoking, were socioeconomically deprived, or lived in rural areas. They were also less likely to have had a chest X-ray requested by their GP in the four months before diagnosis.

While the study found associations between factors, it cannot say for certain whether symptoms were missed. For example, there may be a variety of reasons why a chest X-ray was not requested – some people may not have had or reported symptoms of lung cancer, or may not have wanted further investigations.

Smoking is still the biggest risk factor for developing lung cancer, so visit the NHS Choices Stop Smoking guide for ways to help you quit.

You should always visit your GP if you develop a persistent cough, cough up blood, or have persistent breathlessness.

 

Where did the story come from?

The study was carried out by researchers from the University of Nottingham and Nottingham City Hospital. It was funded by the Roy Castle Lung Cancer Foundation.

The study was published in the peer-reviewed medical journal Thorax on an open access basis, so it is free to read online (PDF, 727.2kb).

The media focused on blaming GPs for missing or delayed cancer diagnosis without considering that this research cannot tell us for certain what the causes of early lung cancer deaths are. It can only identify links that need to be investigated further.

This could include collecting details the current study did not have on individual patients, such as why they were visiting their GP, other illnesses, if they had any symptoms, and also whether the lung cancer was actually the cause of death.

There are anecdotal reports that many "hard core" smokers mistake the persistent cough associated with lung cancer for a "smoker's cough". This could contribute towards the pattern of late diagnosis seen in this study.

 

What kind of research was this?

This was a cohort study looking at the factors linked with early death from lung cancer in the UK. This included looking at whether there was any link with the number of GP visits and if a chest X-ray had been performed in the four months prior to diagnosis.

The researchers say the UK has poor lung cancer survival rates compared with other countries, and this could be associated with late diagnosis.

This type of study is appropriate for looking at this question, and it benefits from using data recorded at the time.

However, as the data wasn't collected expressly for this study, there may be information missing that the researchers would have liked to have but didn't get (for example, why the person went to the GP in the first place).

The main limitation is that although the study can identify associations between factors, it cannot show with certainty whether they definitely contributed to the outcome (early death).

 

What did the research involve?

The researchers looked at the records of adults over the age of 30 who had been diagnosed with lung cancer between January 2000 and January 2013.

They compared people who survived for more than 90 days following diagnosis with those that did not in terms of:

  • characteristics (gender, socioeconomic level and smoking status)
  • number of visits to the GP in the four months before the lung cancer diagnosis
  • if a chest X-ray had been requested by the GP in the four months before diagnosis

People were excluded from the study if they had been registered with their GP for less than 12 months.

The researchers obtained the data from a database called The Health Improvement Network (THIN), which contains data on symptoms, diagnoses, prescriptions, medical investigations and their results entered by GPs during appointments or based on information sent to the GP by secondary care.

 

What were the basic results?

The researchers identified 20,142 people who had been diagnosed with lung cancer from 444 GP practices. Of these:

  • 5% were only diagnosed once they died (diagnosis only on their death certificate)
  • 10% died within 30 days of the diagnosis
  • 15% died between 30 and 90 days of diagnosis
  • 70% survived for longer than 90 days

People who died early (within 90 days of diagnosis) had visited their GP on average (median) five times in the four months before diagnosis, compared with four times for those who survived for longer. People who had a chest X-ray requested by their GP were less likely to die within 90 days.

When looking at each GP practice as a whole, people registered at practices that requested more chest X-rays were more likely to die early (comparison of practices with highest rates versus those with the lowest: odds ratio [OR] 1.41, 95% confidence interval [CI] 1.29 to 1.55).

Characteristics associated with an increased likelihood of dying early were:

  • being male (OR 1.17, 95% CI 1.10 to 1.24)
  • being a current smoker (OR 1.43, 95% CI 1.28 to 1.61)
  • being older (aged 80 years or more compared with aged 65 to 69: OR 1.80, 95% CI 1.62 to 1.99)
  • being socially deprived (Townsend quintile five [most deprived] versus one [least deprived] OR 1.16, 95% CI 1.04 to 1.30)
  • living in a rural area (OR 1.22, 95% CI 1.06 to 1.41)

 

How did the researchers interpret the results?

The researchers concluded that, "Patients who die early from lung cancer are interacting with primary care prediagnosis, suggesting potentially missed opportunities to identify them earlier.

"A general increase in CXR [chest X-ray] requests may not improve survival; rather, a more timely and appropriate targeting of this investigation using risk assessment tools needs further assessment."

 

Conclusion

This study found people who die early after their lung cancer diagnosis (within three months) were less likely to have had a chest X-ray and tended to have more GP visits on average in the four months prior to their diagnosis than those who lived longer.

The researchers suggest that this could indicate there are "missed opportunities to identify them earlier", and this is what the media has focused on. 

While the study found an association with the number of GP visits, the difference is relatively small (one visit on average). There are many factors that could have accounted for the number of visits made to the GP, as well as other issues that were not assessed in this study. These include:

  • whether the people in each group actually had (or reported to their GP) symptoms of lung cancer
  • whether the lung cancer was the cause of death or the person died from other causes 
  • whether there were any other (non-cancer) illnesses present that may have been the reason for the GP visits
  • whether a patient preferred not to have investigations such as a chest X-ray

The researchers also did not have information on the stage of people's lung cancer when they were diagnosed to confirm that these people were diagnosed late.

Some of the other findings of the study – such as the fact that those dying early tended to be older, male smokers who lived rurally and in more socially deprived areas – have not been focused on by the media. These findings may offer insights into those who might, for example, be targeted for lung cancer symptom awareness.

Lung cancer remains one of the most common types of cancer in the UK, and has one of the lowest survival outcomes. Important research such as this investigates reasons why this might be, and how the outlook could be improved.

One of the problems with lung cancer is there are usually no signs or symptoms in the early stages of the disease. The symptoms that people may develop later on include:

  • a persistent cough
  • coughing up blood
  • persistent breathlessness
  • unexplained tiredness and weight loss
  • an ache or pain when breathing or coughing

You should always see your GP as soon as possible if you have any of these symptoms.

Smoking is still the biggest risk factor for developing lung cancer – if you smoke, quitting is the best way to reduce your chances of developing this disease. Visit the Stop smoking guide for ways to help you quit.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

GPs in UK 'missing opportunities' to spot lung cancer. BBC News, October 14 2014

Lung cancer deaths so high 'because GPs failing to spot symptoms'. Daily Mirror, October 13 2014

Lung cancer is diagnosed far too late: Third of patients with the condition are told just 90 days before they die. Mail Online, October 14 2014

Links To Science

O'Dowd EL, McKeever TM, Baldwin DR, et al. What characteristics of primary care and patients are associated with early death in patients with lung cancer in the UK? (PDF, 727.2kb). Thorax. Published online October 13 2014

Categories: NHS Choices

Can we count on counting calories?

Mon, 13/10/2014 - 13:00

It's a concept at the cornerstone of most diets: counting the calories of your food intake so you don't go over the limit.

But just how accurate are calorie labels? And are some calories more "equal" than others?

There is a seemingly endless stream of media articles focusing on the latest diet wonder, whether it involves intermittent fasting or feasting on fats.

Although they protest otherwise, most miracle weight loss programmes come down to calorie restriction.

Behind the Headlines takes a look at the science behind calorie counting, examining why it may be only one aspect of healthy, sustainable weight loss.

 

What's in a calorie?

A calorie is a unit of measurement of how much energy is stored in a mass of food.

Confusingly, the "calories" we talk about in daily life are officially described as kilocalories, or kcals, and this is how they appear on food labels. One calorie equals one kilocalorie.

A single calorie is defined as having approximately the amount of energy needed to raise the temperature of one kilogram of water by 1C. 

 

Calorie allowances

An average man needs around 2,500kcal a day. For an average woman, that figure is around 2,000kcal a day.

These values can vary widely depending on levels of physical activity. For example, some Olympic swimmers have reported eating as many as 12,000 calories a day when they are competing.

 

Links To Science

Barr SB, Wright JC. Postprandial energy expenditure in whole-food and processed-food meals: implications for daily energy expenditure. Food and Nutrition Research. July 2 2010

Bleich SN, Wolfson JA, Vine S, Wang YC. Diet-beverage consumption and caloric intake among US adults, overall and by body weight. American Journal of Public Health. Published online March 2014

Carmody RN, Wrangham RW. The energetic significance of cooking. Evolutionary Anthropology. October 2009

Daumit GL, et al. A Behavioral Weight-Loss Intervention in Persons with Serious Mental Illness. New England Journal of Medicine. April 25 2013

Deckersbach T, Das SK, Urban LE, et al. Pilot randomized trial demonstrating reversal of obesity-related abnormalities in reward system responsivity to food cues with a behavioral intervention. Nutrition and Diabetes. Published online September 1 2014

Feinman RD, Fine EJ. 'A calorie is a calorie' violates the second law of thermodynamics. Nutrition Journal. July 28 2004

Fonseca-Azevedo K, Herculano-Housel S. Metabolic constraint imposes tradeoff between body size and number of brain neurons in human evolution. PNAS. October 22 2012

Frost G, Sleeth ML, Sahuri-Arisoylu M, et al. The short-chain fatty acid acetate reduces appetite via a central homeostatic mechanism. Nature Communications. Published online April 29 2014 

Grilo CM, et al.  Cognitive-behavioral therapy, behavioral weight loss, and sequential treatment for obese patients with binge eating disorder: a randomized controlled trial. Journal of Consultant Clinical Psychology. October 2011

Johnston BC, Kanters S, Bandayrel K, et al. Comparison of weight loss among named diet programs in overweight and obese adults: a meta-analysis. JAMA. September 3 2014

National Institute for Health and Care Excellence. Managing overweight and obesity in adults – lifestyle weight management services. May 2014

Nguyen BT and Powell LM. The impact of restaurant consumption among US adults: effects on energy and nutrient intakes. Public Health Nutrition. Published online July 30 2014

Novotny JA, Gebauer SK, Baer DJ. Discrepancy between the Atwater factor predicted and empirically measured energy values of almonds in human diets. American Journal of Clinical Nutrition. July 3 2012 

Reddy ST, et al. Effect of low-carbohydrate high protein diet on acid-base balance, stone forming propensity and calcium metabolism. American Journal of Kidney Disease. August 2002

Santos FL, et al. Systematic review and meta-analysis of clinical trials of the effects of low carbohydrate diets on cardiovascular risk factors. Obesity Review. Published online August 21 2012

Categories: NHS Choices

'Poo in a pill' may help treat C. difficile infection

Mon, 13/10/2014 - 12:00

“Capsules containing frozen faecal material may help clear up C. difficile infections,” BBC News reports.

While the prospect may sound stomach-churning, swallowing somebody else’s "poo" may help treat symptoms such as chronic diarrhoea, which can be life-threatening. 

The headline is based on new research on 20 people with recurrent diarrhoea caused by C. difficile that was not cured with standard antibiotics.

C. difficile is a bacterium that is normally present harmlessly in the gut, but in people who have received courses of antibiotics, there can be an overgrowth of this bacteria, resulting in persistent, often severe, diarrhoea.

The research team gave the patients 30 capsules of frozen faecal matter containing gut bacteria from four healthy donors, in an effort to replace the illness-causing bacteria with non-harmful varieties.

No serious side effects were reported in the small group, and diarrhoea was cured in 14 of the 20 people assessed over an eight-week period. All six non-responders were retreated and four were then cured, taking the total to 18 out of 20 no longer suffering from diarrhoea. Self-reported health scores of the participants also improved.

Larger and longer clinical trials will now need to take place to prove it works, and the treatment’s safety needs to be thoroughly investigated. This treatment concept definitely falls into the “don’t try this at home” category.

The results also have a very specific application to recurrent C. difficile infection and do not relate to other causes of diarrhoea, or other digestive conditions.

 

Where did the story come from?

The study was carried out by researchers from Massachusetts-based hospitals and was funded by the hospital departments themselves. One of the authors declared receiving funds to conduct a clinical trial related to the treatment of C. difficile (not the current study). The study builds on previous research, published in 2012, involving mice

The study was published in the peer-reviewed medical journal JAMA and has been published on an open access basis, so is free to read online.

BBC News reported the story accurately, including warnings to tempted readers not to make their own "home brew” faecal capsules as a way of tackling diarrhoea, which could be dangerous.

The Independent’s claim that these frozen capsules are a definitive cure for C. difficile is premature, given the small size of the study.

It is important to note that these findings are specific only to people hospitalised with C. difficile-related diarrhoea. This is a specific cause of diarrhoea, which is completely different from the diarrhoea and vomiting bugs of the winter season, which are usually caused by viruses. Similarly, diarrhoea may not always be caused by infection at all. For example, inflammatory bowel diseases or bowel cancer can cause diarrhoea. As such, the study has a specific application, and does not relate to "diarrhoea treatment” in general.

 

What kind of research was this?

This was a feasibility study looking at whether it was possible to treat severe diarrhoea caused by a specific gut bug (C. difficile) using frozen faecal matter (poo) capsules from unrelated donors.

C. difficile is a bug that is normally present harmlessly in the gut, but in people (usually hospitalised) who have received courses of antibiotics, there can be an overgrowth of this bacteria, resulting in diarrhoea that can sometimes be severe and even life-threatening.

The rationale for faecal bacterial transplant is that the introduction of “normal” gut bacteria from a healthy donor should rebalance the system, curing the illness.

Faecal transplants have been carried out before, but using fresh donor stools and infusions. This raises a number of problems and complexities, which the researchers sought to address by developing an easy-to-take pill instead.

Feasibility studies are small studies aiming to show whether a new idea might work and to get an idea of its safety. These early studies normally involve a small number of people. If it does seem to work and appears safe, then larger, more methodologically robust studies can occur. These studies aim to establish better proof that the technique is both effective and safe. Feasibility studies on their own do not prove this; they are a stepping stone to more robust investigations.

 

What did the research involve?

This study recruited 20 people who had had at least three episodes of mild to moderate C. difficile infection and failed to get better with standard treatment, or who had at least two episodes of severe C. difficile infection requiring hospitalisation. Their average age (median) was 64.5 years, but ranged from 11 to 89.

Researchers created capsules containing frozen faecal matter, including bacteria, from four healthy volunteers. All 20 participants were given 15 of these capsules on two consecutive days and followed for up to six months to see if their symptoms resolved and if they had any side effects.

The main outcomes of interest were:

  • resolution of the diarrhoea without recurrence up to eight weeks
  • safety and side effects

Secondary outcomes included self-reported wellbeing and daily number of bowel movements.

 

What were the basic results?

The main results were:

  • No serious side effects were reported.
  • Resolution of diarrhoea (up to eight weeks without recurrence) occurred in 14 of the 20 patients (70%) after a single treatment course of the capsules.
  • The remaining six participants had a second treatment round, leading to a further four resolutions. This took the total of successful treatments to 18 out of 20 (90%) with one or two treatments.
  • Patients needing a second treatment to obtain resolution of symptoms had generally lower pre-treatment self-reported health scores.
  • Daily number of bowel movements decreased on average from five (interquartile range [IQR] three to six) the day prior to treatment to two (IQR one to three) at day three, and one (IQR one to two) at week eight.
  • Self-ranked health scores significantly improved on a scale of one to 10 from five before treatment (IQR five to seven) to eight after treatment (IQR seven to nine).

 

How did the researchers interpret the results?

The researchers concluded that, “This preliminary study among patients with relapsing C. difficile infection provides data on adverse events and rates of resolution of diarrhoea following administration of FMT [faecal microbiota transplantation] using frozen encapsulated inoculum from unrelated donors. Larger studies are needed to confirm these results and to evaluate long-term safety and effectiveness.”

 

Conclusion

This study showed it was possible to resolve diarrhoea symptoms in people with recurrent and treatment-resistant C. difficile diarrhoea using frozen capsules of someone else’s faeces. The pill form used is an improvement on previous methods, which require fresh stools and more complex delivery mechanisms.

The study was a small feasibility study, meaning it does not provide robust proof that the technique is yet effective or safe. It did not, for example, have a control group, so we don’t know how many people would have got better on their own. Larger, more robust, clinical trials are needed to prove its effectiveness and safety before it is known whether the experimental pill could have the potential to be developed into a new treatment.

Nonetheless, the study did show that the capsules appeared feasible, initially safe and somewhat effective, so further trials will no doubt follow to develop the technique further.

This study specifically investigated diarrhoea caused by C. difficile, so it is not currently known whether rebalancing a person’s gut bacteria using a pill containing bacteria from another person could have wider applications to other bugs and gut infections.

A final unanswered question is how many people would actually be willing to use the treatment. Given the potential severity of the condition it aims to treat, and the likely tasteless nature of the pill, uptake could be high. Nevertheless, the prospect of ingesting somebody else’s "poo" may be too hard to swallow for some.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Faecal capsules 'may help stop gut infection'. BBC News, October 12 2014

Capsules can cure C difficile – but don't ask what's in them. The Independent, October 12 2014

Links To Science

Youngster I, Russell GH, Pindar C, et al. Oral, Capsulized, Frozen Fecal Microbiota Transplantation for Relapsing Clostridium difficile Infection. JAMA. Published online October 11 2014

Categories: NHS Choices

Fruit juice link to high blood pressure not proven

Mon, 13/10/2014 - 10:54

"Does drinking fruit juice give you high blood pressure?," the Mail Online asks, as an Australian study found people who reported a daily intake of fruit juice tended to have slightly higher blood pressure. This finding, the researchers argue, is likely down to the high sugar content of fruit juices.

But this and other headlines exaggerated the results of a small, potentially unreliable and unrepresentative study.

In fact, the study showed there was a link between daily fruit juice consumption and central blood pressure in a group of 130 largely healthy 50 to 70 year olds.

People who drank juice daily had a systolic pressure (the upper figure in a blood pressure reading) 3 to 4mmHg higher than those who drank juice rarely or occasionally. But there was no link when measuring blood pressure in the arm using standard measures. 

The media reports focus on the possibility that the slight raise in blood pressure could increase a person's risk of a variety of blood pressure-related diseases, such as a heart attack. But it's unclear whether this small difference would have a meaningful impact on health.

As both juice consumption and blood pressure were assessed at the same time, the study does not prove that fruit juice caused the raised blood pressure. There could be other dietary or physical activity factors accounting for this link, or there could be reverse causation (people drank fruit juice because they were worried about their blood pressure).

Overall, this study alone does not provide evidence that fruit juice increases blood pressure or, by proxy, raises the risk of heart attack or angina. 

Nonetheless, it is important to note that fruit juice is high in sugar, so it's recommended you drink no more than 150ml a day for the sake of your teeth – and to help keep your calories down.

 

Where did the story come from?

The study was carried out by researchers from Swinburne University of Technology and Monash University Australia, and was funded by Swisse Wellness, a company that sells vitamins, supplements, "superfoods" and skincare products, but – notably – not fruit juices.

It was published in the peer-reviewed medical journal Appetite.

The UK media usefully noted the large amount of sugar present in fruit juice, but the Daily Express' statement that fruit juice is a "health danger" that is "putting millions at risk" – while attention-grabbing – is highly subjective. It also doesn't reflect the results of the study, which does not prove fruit juice is a danger.

 

What kind of research was this?

This was a cross-sectional study looking at the link between regular fruit juice consumption and blood pressure.

The authors outline that, "Despite a common perception that fruit juice is healthy, fruit juice contains high amounts of naturally occurring sugar without the fibre content of the whole fruit."

They say, therefore, that regular fruit juice consumption, like soft drink consumption, represents a source of excess sugar in the modern diet.

Excess sugar intake, the team say, is linked to higher blood pressure, obesity and being overweight, and raises the risk of developing a number of associated diseases, such as cardiovascular disease and stroke.

The researchers point to previous research suggesting a link between higher sugar consumption and higher blood pressure, but wanted to investigate the specific role of fruit juice in this relationship.

As this was a cross-sectional study, it cannot prove fruit juice causes higher blood pressure. There may be other explanations and factors at play, such as dietary, physical activity or other lifestyle habits.

It also cannot exclude the possibility of reverse causality, where people with high blood pressure may be consuming more fruit juice because of health concerns, rather than vice versa.

Ultimately, a randomised control trial would be needed to prove that fruit juice – or any other food or drink item representing a source of excess sugar – causes sustained blood pressure increases.

 

What did the research involve?

The researchers asked a group of 160 adults (aged 50 to 70) about their food and drink habits over the past year. On the same day, the team took their blood pressure using two different measures.

One was the standard blood pressure measurement of the upper arm using a blood pressure cuff (brachial blood pressure), and one estimated pressure in the main blood vessel taking blood from the heart, called central, or aortic, blood pressure.

To do this, a probe was used to measure the waveform of blood in the wrist artery. This information was fed into special software that estimated central pressure.

The main analysis looked for links between fruit juice consumption categories and the one-off blood pressure readings at one or both sites.

Fruit juice consumption was categorised as follows:

  • rare – combined those who never drank juice with those consuming no more than three times a month
  • occasional – those consuming juice once a week up to five to six times a week
  • daily – once or more a day

The researchers used two measures of blood pressure (central and brachial), as there is debate about which is best to use in terms of predicting future disease risk.

To be included in the study, people had to be free of major neurological and psychiatric illness, cardiovascular disease, currently be a non-smoker, and have no history of alcohol or drug abuse.

The main analysis was adjusted to reduce the influences of the following confounders:

  • age
  • gender
  • height
  • weight
  • mean arterial pressure
  • heart rate
  • cholesterol and blood pressure treatments

 

What were the basic results?

There were no differences found between the standard blood pressure measure in the arm and the different juice groups, but differences were found for central blood pressure.

Those who consumed fruit juice daily, versus rarely or occasionally, had significantly higher central systolic blood pressure (the upper of the two-figure blood pressure measurement – in a measure of 140/80, 140 is the systolic blood pressure).

They also had higher readings for central pulse pressure and other measures looking at the heart rate and blood pressure wave forms (central augmentation pressure, central augmentation index and lower pulse pressure amplification).

Central systolic blood pressure was 3 to 4mmHg higher for those who consumed fruit juice daily rather than rarely or occasionally.

 

How did the researchers interpret the results?

The researchers concluded that, "more frequent fruit juice consumption was associated with higher central BPs [blood pressures]".

 

Conclusion

This cross-sectional study found a link between regular fruit juice consumption and slightly increased central blood pressure in a group of 130 largely healthy 50 to 70 year olds. People who drank juice daily had a systolic pressure (the upper figure) 3 to 4mmHg higher than those who drank juice rarely or occasionally.

However, when measuring the blood pressure in the standard way, using an inflatable cuff around the arm, there was no link. 

The media reports focus on the possibility that the slight raise in blood pressure could increase a person's risk of a variety of blood pressure-related complications. But it is unclear whether the small difference in systolic pressure would have had clinically significant meaning for the individual.

Similarly, it is not clear why only one of the blood pressure measures was affected and not both, if indeed there was a real link between fruit juice and blood pressure.

Also, the link was only found with systolic blood pressure (arterial pressure when the heart contracts) and not for diastolic (arterial pressure when the heart relaxes), when both figures are equally relevant in terms of the clinical significance of raised blood pressure.

This might be caused by some of the additional limitations in the study, which all introduced error and uncertainty into the findings. These limitations include:

  • relying on people's ability to accurately recall their food and drink habits over the last year, which may be inaccurate
  • being able to estimate central blood pressure accurately
  • only measuring blood pressure once, which is less reliable than measuring it many times on different days to get an average reading
  • all participants were 50 to 70 years old, and the effects in other age groups were not tested
  • it was not clear how long established the juice drinking habits were – we only know about consumption in the previous year

Furthermore, the analysis made no adjustment for other sources of sugar in the diet. Given that fruit juice was being investigated because it represented a source of additional sugar in the diet, this is an important omission.

Without knowing about other sources of sugar, it is difficult to tell how important fruit juice was in the bigger picture, or how much of a person's overall sugar intake was from juice. The role of other sugary drinks or foods is likely to be very important, but was not accounted for in the analysis.

The lack of information on other dietary and physical activity patterns also makes it difficult to exclude the possibility of reverse causality. Based on this cross-sectional analysis, it could equally be possible that people with raised blood pressure could be drinking more fruit juice in addition to other healthy lifestyle changes, rather than that fruit juice is causing the high blood pressure.

So, on its own, this study does not justify a change in fruit juice drinking habits relating to blood pressure, as the risk is unproven. A more robust study design would be needed to properly prove whether this was the case.

However, it serves to remind us that fruit juice contains a lot of sugar, something many people may not be fully aware of. Some juice drinks can contain as much sugar, and sometimes more, than a can of coke.

Any high-sugar food or drink should be consumed in moderation as part of a wide and varied diet, rich in unprocessed fruit and vegetables, and generally low in sugar.

Being aware of the sugar content of food is one of many simple ways to maintain a healthy weight and minimise your risk of developing weight-related diseases now or in the future.

Find out more about how sources of added sugar can sneak into your diet.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Does drinking fruit juice give you high blood pressure? New study finds a regular morning glass of orange juice significantly raises health risk. Mail Online, October 11 2014

Health danger in FRUIT JUICE: Millions put themselves at risk by drinking a glass DAILY. Daily Express, October 11 2014

Links To Science

Pase MP, Grima N, Cockerell R, Pipingas A. Habitual intake of fruit juice predicts central blood pressure. Appetite. Published online September 30 2014

Categories: NHS Choices

Is a cure for type 1 diabetes 'within reach'?

Fri, 10/10/2014 - 12:25

"Type 1 diabetes cure within reach after breakthrough," The Independent reports after researchers have managed to "coax" human stem cells into becoming insulin-producing cells.

Type 1 diabetes is an autoimmune condition where the body's own immune system destroys the insulin-producing cells of the pancreas. Insulin is a hormone that plays a vital role in regulating blood glucose levels.

There is currently no "cure" for type 1 diabetes and no way to replace these destroyed cells, making the person reliant on lifelong insulin injections.

This study aimed to see if it would be possible to develop these insulin-producing cells from stem cells in the laboratory. 

The researchers demonstrated they were able to successfully produce large numbers of functioning stem cell-derived cells that looked structurally similar to normal pancreatic cells, and produced insulin in response to glucose in the same way.

The function of these cells was demonstrated both in the laboratory and when transplanted into live mice, including mice genetically engineered to have diabetes.

The findings are positive, but the research is still in the very early stages. Further development will be needed to see whether stem cell-derived pancreatic cells could function normally in people with type 1 diabetes.

There is also the question as to whether the transplanted cells could also be targeted by the body's immune system.

Overall, it is too early to know whether there could one day be a complete "cure" for type 1 diabetes.

 

Where did the story come from?

The study was carried out by researchers from Harvard University and was funded by the Harvard Stem Cell Institute, the National Institute of Health, Helmsley Charitable Trust, the JPB Foundation and personal contributions.

It was published in the peer-reviewed scientific journal, Cell.

The UK media's reporting of the study was accurate, but talks of a "cure" for type 1 diabetes are premature.

As the authors of the study acknowledge themselves, "Much work remains to be done to achieve any of these therapeutic, disease-modelling, drug discovery or tissue engineering goals."

 

What kind of research was this?

This was a laboratory study that aimed to develop a generation of insulin-producing pancreatic beta cells from stem cells. 

Type 1 diabetes is an autoimmune condition where the body's own immune system for some reason destroys beta cells, making the person reliant on lifelong insulin injections. There is currently no "cure" for type 1 diabetes and no way to replace these destroyed cells.

As the researchers say, the discovery of human pluripotent stem cells (hPSC) offers a great deal of potential for medical innovation. This is because hPSCs can be converted into other specialist cell types, such as insulin-producing cells.

This then opens up the possibility of generating replacement cells and tissues in the laboratory, which could be used for disease treatment.

This study examines whether hPSCs in the laboratory could be instructed (via manipulation of signalling pathways) to develop into functioning pancreatic beta cells.

 

What did the research involve?

The researchers first cultured different pluripotent stem cell lines and trialled various different laboratory approaches. This was so they could make these differentiate into functioning cells that had the genetic characteristics of pancreatic beta cells.

The stem cell-derived pancreatic beta cells were then incubated in glucose solution to see if this stimulated them to produce insulin. A sequence of further glucose challenges (tests that see how the cells respond to glucose) at increasing concentrations then followed.

The researchers then compared these results with those of normal adult beta cells.

They got further confirmation of the cells' functioning by looking at changes in calcium levels within the cells, as beta cells sense changing glucose levels through calcium signalling. This helps them regulate blood glucose levels as required.

The structure of the stem cell-derived pancreatic cells was then more closely analysed in the laboratory.

As the next stage of the experiment, the stem cell-derived pancreatic cells were then transplanted into live mice with a suppressed immune system.

Two weeks after transplantation, these mice then had various glucose challenges, with blood samples taken to check their blood glucose and insulin levels. This was again compared with transplantation of normal adult beta cells.

Finally, they looked at the effects of transplanting these cells into genetically engineered "diabetic" mice.

 

What were the basic results?

Overall, 75% of the stem cell-derived pancreatic beta cells responded to high glucose challenges, which was similar to that for normal adult beta cells.

The amount of insulin secreted in response to glucose per stem cell-derived cell was also similar to that of normal beta cells. The cellular calcium response to glucose was also similar between the stem cell-derived cells and the normal cells.

The researchers further demonstrated that the structure and protein expression of the stem cell-derived cells was similar to the normal pancreatic cells.

When the stem cell-derived pancreatic cells were transplanted into the mice, the mice successfully secreted insulin into the bloodstream within two weeks.

In the glucose challenge, 73% of the mice with these transplanted cells (27 of 37 animals) showed increased blood insulin levels. This was in comparison to 75% (9 of 12) of those transplanted with normal pancreatic cells.

As a final stage, when transplanted into "diabetic" mice, the stem cell-derived pancreatic cells helped stop the rapidly worsening increasing blood sugar normally observed in these animals. By four months after transplantation, only one out of six of these diabetic mice had died.

 

How did the researchers interpret the results?

The researchers concluded that functional pancreatic beta cells can be generated from human pluripotent stem cells in the laboratory.

The results demonstrate that they function similarly to normal adult beta cells, both in the laboratory and in the live mouse model.

 

Conclusion

This is promising early-stage research into the possible generation of insulin-producing pancreatic beta cells from stem cells in a laboratory.

The researchers demonstrated that they were able to successfully produce large numbers of functioning stem cell-derived cells that looked structurally similar to normal beta cells and produced insulin in response to glucose in the same way.

The successful function of these cells was demonstrated both in the laboratory and when transplanted into mice, including mice genetically engineered to have diabetes.

There is currently no "cure" for type 1 diabetes and no way to replace these destroyed cells. This stem cell research, which holds promise for a possible generation of replacement pancreatic cells, is therefore encouraging.

However, research is still in the very early stages, with studies only having been carried out on a small number of live mice.

Much further development is needed to see whether it could be possible to perform human trials to see whether stem cell-derived pancreatic cells could function normally in people with type 1 diabetes.

Various questions still need to be answered, including whether the transplanted cells could also be targeted by the body's immune system.

Overall, the research is promising, but it is too early to know whether there could one day be a complete "cure" for type 1 diabetes.

Analysis by Bazian. Edited by NHS ChoicesFollow Behind the Headlines on TwitterJoin the Healthy Evidence forum.

Links To The Headlines

Type 1 diabetes cure within reach after breakthrough that could spell end of insulin injections for millions. The Independent, October 9 2014

Cure for Type 1 diabetes imminent after Harvard stem-cell breakthrough. The Daily Telegraph, October 9 2014

Type 1 diabetes breakthrough using stem cell research raises hope for cure. The Guardian, October 10 2014

Could this stem cell breakthrough offer an end to diabetes? Expert promised his sick son he'd find a cure. Daily Mail, October 10 2014

Scientists close to a non-insulin cure for diabetes. The Times, October 10 2014

Links To Science

Pagliuca FW, Millman JR, Gürtler M, et al. Generation of Functional Human Pancreatic β Cells In Vitro. Cell. Published online October 9 2014

Categories: NHS Choices

Antibiotic resistance continues to rise

Fri, 10/10/2014 - 11:29

"Antibiotic resistance continues to rise," BBC News reports as, despite warnings, the number of antibiotic prescriptions in the UK continues to soar, as do new cases of resistant bacteria.

Other news reports take different slants on the story, with The Daily Telegraph blaming the rise on hospitals and out of hours GPs.

The news follows the publication of a new report by Public Health England on the English surveillance programme for antimicrobial utilisation and resistance (ESPAUR), which reports the change in antibiotic prescribing and resistance over recent years.

The report highlights a number of key findings, including a year on year increase in antibiotic prescribing in England, with the majority of antibiotic prescribing taking place in general practice. There also seems to be variation across the UK, with areas with higher antibiotic prescribing also having higher rates of resistant infections.

Public Health England hopes this report will enable general practices and hospitals to compare their data with regional and national trends. They could then see if their rates are higher than other areas, and investigate why and if they can reduce these. This will also provide a baseline measure from which to track changes in both prescribing and resistance in England.

 

What is antimicrobial resistance?

Antimicrobial resistance is a global health threat.

Antimicrobials are drugs used to treat an infectious organism, and include antibiotics (used to treat bacteria), antivirals (for viruses), antifungals (for fungal infections) and antiparasitics (for parasites).

When antimicrobials are no longer effective against infections they were previously effective against, this is called antimicrobial resistance. Regular exposure to antimicrobials prompts the bacteria or other organisms to change and adapt to be able to survive these drugs.

As the report says, the problem has been around for decades, but in the past it was seen as less of a problem as new antibiotics were regularly being developed. 

However, nowadays fewer new antibiotics are being developed, meaning we have fewer options and stronger and stronger drugs in our antibiotics armoury have to be used to treat common infections once they become resistant. This means we are now facing a possible future situation where we will be without effective antibiotics.

 

What does the report say about current antimicrobial resistance in England?

The report highlights the following:

  • There has been an increase in the number of bloodstream infections between 2010 and 2013, and an increase in the number of cases where resistance was identified. For example, during this three-year period the number of bloodstream infections caused by E. coli increased by 12%.
  • The proportion of E. coli bacteria with resistance to antibiotics increased between 2001 and 2006-07 and then decreased, but has risen again between 2010 and 2013. Roughly around one in five infections involving E. coli bacteria in 2013 were resistant to a commonly used antibiotic (ciprofloxacin), an 18% increase from 2010. Around 1 in 10 infections were resistant to the stronger antibiotics (third-generation cephalosporins and gentamicin), a 27-28% increase.
  • Looking across England there is variation in resistance, with ciprofloxacin resistance ranging from 25% in London to 12% in Cumbria, Northumberland and Tyne and Wear. Cephalosporin resistance ranged from 15% in London to 6% in Devon, Cornwall and the Isles of Scilly, and gentamicin resistance ranged from 15% in London to 5% in Durham, Darlington and Tees. 
  • There have been increases in bloodstream infections caused by some bacteria (K. pneumoniae), while others (S. pneumoniae and Pseudomonas) have shown a decline. With all infections there appears to be a notable variation in resistance rates in different geographical regions.
  • A particular focus was looking at antibacterial resistance to carbapenems – very strong antibiotics widely considered to be "antibiotics of last resort". The data indicates these antibiotics currently remain effective for the treatment of more than 98% of blood infections caused by E. coli or K. pneumonia. But, as the report says, this should not lead to complacency. Despite the small proportion of bacteria resistant to carbapenems, there has still been a year on year increase in the number of bacteria able to produce enzymes capable of destroying this antibiotic.

 

What does the report say about current antimicrobial prescribing in England?

The report highlights the following trends in antimicrobial prescribing:

  • Between 2010 and 2013, total antibiotic prescribing increased by 6% – general practice prescribing increased 4%, prescribing to hospital inpatients increased by 12%, and other community prescriptions (such as by dentists, out of hours prescribers, nurses, and other non-medical prescribers) increased by 32%.
  • In 2013, 27.4 out of every 1,000 inhabitants in England were taking a prescribed dose of antibiotics each day, with 79% of these prescriptions occurring in general practice, 15% in hospital and 6% being other community prescriptions (predominantly dentists).
  • The highest combined general practice and hospital antibiotic prescriptions were in Merseyside, with 30.4 per 1,000 inhabitants per day taking antibiotics, more than 30% higher than Thames Valley, with the lowest prescription rates (22.8 per 1,000 inhabitants per day). The highest prescription rate from general practice alone was Durham, Darlington and Tees (26.5 per 1,000 inhabitants per day), which was more than 40% higher than London (18.9 per 1,000 inhabitants per day). It was suggested the lower GP prescribing in London may reflect different healthcare access and delivery in the capital, where there may be a shift in prescribing to local hospitals and private healthcare providers.
  • Overall, the antibiotic use per 1,000 inhabitants per day is thought to be an underestimate of total consumption, as it does not include private prescriptions, which are not recorded as part of ESPAUR at present. The reasons for the increase in consumption are unknown, but may represent changes in the number of patients presenting to medical care with infections requiring antibiotics, or it could be overprescribing of antibiotics by doctors (or dentists). The report says the increase in other community prescriptions needs to be explored to assess whether general practice prescribing is being displaced to out of hours treatment centres.
  • In 2013, 66 different antibiotics were prescribed in both general practice and hospital settings, with a top 15 of these antibiotics accounting for 98% of GP prescriptions and 88% of hospitals. These top antibiotics include penicillins, tetracyclines and macrolides (such as erythromycin). Over the past four years, prescribing of penicillins has increased by 3% and macrolides by 6%.
  • Generally, in general practice the prescription of broad spectrum antibiotics (that are less specific to particular bacteria and cover a wide range of different bacteria) has decreased over recent years, while in hospital the prescription of broad spectrum antibiotics has increased.
  • Comparing the UK with other EU countries, we are said to be in the mid-range for community prescriptions of antimicrobials. But for antibiotics prescribing in hospitals, the UK had rates that were more than twice the average (median) in the EU. However, this may relate at least in part to different prescribing and recording of prescription practices in UK hospitals.

 

What is being done to help?

As the report highlights, antibiotic prescribing and antibiotic resistance are inextricably linked, and overuse and incorrect use of antibiotics are major drivers of resistance.

The Chief Medical Officer for England highlighted the problem of antimicrobial resistance in the 2013 annual report, which led to the UK cross-government five-year (2013-18) antimicrobial resistance strategy.

This is the first report from the English surveillance programme for antimicrobial utilisation and resistance (ESPAUR). Their key aims are to develop surveillance systems to measure both antimicrobial prescribing and resistance, and to measure the impact of antimicrobial prescribing on antimicrobial resistance and patient and public safety.

The data in this report provides national and regional surveillance of antibiotic resistance and antibiotic use trends from 2010 to 2013. Public Health England cautions these are just single snapshots of data, so will require further investigation. They say further validation and exploration of the findings is needed.

The report highlighted that when comparing the maps of antibiotic prescribing and resistance across regions, areas with high prescribing in general have higher resistance levels. Primary and secondary care organisations are advised to audit their own prescription data to compare with regional and national trends.

Knowledge that their consumption is higher than national trends, and assessment of the reasons for this, should help them develop strategies to improve their prescribing as needed.

This information will provide a baseline measure from which to track changes in both prescribing and resistance in England.

 

What can I do to help?

People can help cut antibiotic (or wider antimicrobial) resistance by recognising that many common infections, such as coughs, colds and stomach upsets, are often viral infections that will go away after a short period without treatment ("self-limiting" infections). These infections do not need an antibiotic prescription as they will have no effect.

If you are prescribed an antibiotic (or other antimicrobial), it is also important to make sure you take the full course as prescribed, even if you feel better before you finish the course.

This will reduce the chances of the organisms being exposed to the drug but then surviving, allowing them to develop resistance if they encounter it again.

It will also increase the chances of you getting better, as by not taking a full course you may find the infection comes back and requires further antibiotic prescriptions, which further increases the chances of resistant organisms developing.

 

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Antibiotic resistance rise continues. BBC News, October 10 2014

Doctors urged to cut antibiotics prescriptions. The Guardian, October 10 2014

Out-of-hours GPs 'are fuelling a huge rise in drug-resistant bacteria': Number of antibiotics handed out at evenings and weekends up by a third since 2010. Daily Mail, October 10 2014

Hospitals and out of hours GPs are driving rise in antibiotics: report. The Daily Telegraph, October 10 2014

Doctors urged to become 'cleverer' in use of antibiotics. ITV News, October 10 2014

Health watchdog issues alert over needless antibiotic prescriptions. Daily Express, October 10 2014

Categories: NHS Choices

Could grapefruit juice protect against diabetes?

Thu, 09/10/2014 - 11:45

“Grapefruit juice 'could be the key to weight loss’,'' is the misleading headline in The Daily Telegraph.

It reports on a study in which mice fed a combination of a high-fat diet and grapefruit juice still put on weight – albeit at a lower rate than mice fed a sugary drink. Their blood sugar levels and insulin sensitivity were also better regulated than mice that did not drink grapefruit juice.

The mice were given either a high-fat diet or a low-fat diet in a range of experiments.

Mice fed a high-fat diet and grapefruit juice had an 18% reduced rate of weight gain compared with mice given sugary water with the same number of calories as the grapefruit juice. They also had 13% lower fasting blood sugar levels. There was no effect on weight gain in mice fed a low-fat diet.

Drinking grapefruit juice improved insulin sensitivity in mice, regardless of their diet (in people, reduced insulin sensitivity can be a sign of impending diabetes).

Grapefruit juice lowered blood sugar as effectively as metformin, a drug widely used to treat people with type 2 diabetes. However, none of the mice actually had diabetes, so this research has little immediate relevance to humans with the condition.

For the time being, people with diabetes should not swap their metformin for grapefruit juice on the basis of this study.

 

Where did the story come from?

The study was carried out by researchers from the University of California and was funded by the California Grapefruit Growers Cooperative, although it had no role in the study design, data collection, analysis or decision to publish.

The study was published in the peer-reviewed science journal PLOS ONE. This is an open-access journal, so the study is freely available to all.

Both the Mail Online and The Daily Telegraph’s headlines incorrectly state that grapefruit juice can help people lose weight. Leaving aside the fact that this study involved mice, rather than humans, none of the mice actually lost any weight – they just differed in the rate they put on weight.

The Daily Express’ headline was also irresponsible, as it suggests that grapefruits “tackle diabetes as well as a leading drug”, with an accompanying picture of a smiling woman (not a mouse) tucking into a grapefruit. None of the reports seemed to mention that the work was funded by the California Grapefruit Growers Cooperative. This doesn’t mean that the study results aren’t correct, but it's worth mentioning so people can make their own conclusions.

The Mail Online does, however, include a balancing comment from the British Dietetic Association, which said that until further trials are carried out in humans, it's too early for people to try grapefruit diets.

Links To The Headlines

Grapefruit juice 'could be the key to weight loss'. The Daily Telegraph, October 8 2014

How grapefruit really can help us lose weight: Drinking fruit's juice when eating fatty food can help reduce weight put on by a fifth. Mail Online, October 9 2014

Study shows grapefruits tackle diabetes as well as leading drug. Daily Express, October 9 2014

Links To Science

Chudnovskiy R, Thompson A, Tharp K, et al. Consumption of Clarified Grapefruit Juice Ameliorates High-Fat Diet Induced Insulin Resistance and Weight Gain in Mice. PLOS One. Published online October 8 2014

Categories: NHS Choices

'Healthy foods expensive' claim is unrealistic

Thu, 09/10/2014 - 10:54

“Healthy food now costs three times as much as junk, study shows,” The Independent reports. It also reports a sharper rise in the cost of fruit and veg over the past decade compared to other types of foods.

This news story is based on research which looked at changes in the price of 94 food items in the UK in the decade from 2002 to 2012. It found that in this period foods classified as healthier (such as fruit and vegetables) were more expensive per calorie than foods high in fat or sugar. The healthy foods increased more sharply in price over time, and in 2012 were three times more expensive on average per calorie than unhealthy foods.

Prices were assessed per 1,000 calories, as this is a standard way of assessing food poverty. However, as healthier foods tend to have a much lower energy density (fewer calories per gram) than less healthy foods, this measure may not always give a realistic comparison of different food choices you might buy. For example, you would need to buy and eat around 30 cucumbers to gain around 1,000 calories, compared to about one 200g packet of ginger nut biscuits (about 20 biscuits).

Given the recent economic climate and also concerns about diet-related health conditions, this is likely to be of interest to policy makers, as well as the public. This sort of information could contribute to discussions about whether changing food pricing could motivate people to eat more healthily. 

 

Where did the story come from?

This research was carried out by researchers at the University of Cambridge and the University of East Anglia. The study was funded by the British Heart Foundation, Cancer Research UK, Economic and Social Research Council, Medical Research Council, the National Institute for Health Research, and the Wellcome Trust, and took place in a UK Clinical Research Collaboration centre. One of the authors was funded by the Gates Cambridge Trust.

It was published in PLOS One, which is a peer-reviewedopen access science journal, so the study is freely available online.

The UK media generally covered this study accurately.

 

What kind of research was this?

This was a time trend study, looking at how the costs of more and less healthy foods changed over time in the UK. They used two sources of routinely available UK government data, as they hoped their method could be a way to routinely monitor how affordability of these foods is changing over time. They say that their study is the first to use UK data to assess price trends by nutrient composition of foods.

The researchers report that diet related ill health has been estimated to cost the NHS £5.8 billion per year – more than smoking, alcohol, or physical inactivity. Although consuming healthier foods is linked to better health outcomes, many people in the UK do not meet healthy eating recommendations. The researchers describe one survey which found that 39% of people rated price as the most important factor in their food choice compared to just 9% who considered a food’s healthiness to be most important.

So if healthier food is more expensive, this could be a significant barrier to people eating more healthily.

 

What did the researchers do?

The researchers selected 94 foods and drinks and classified them as “more healthy” or “less healthy” based on their calorie and nutrient contents. They identified their costs from 2002 to 2012, and compared the prices of the “more healthy” and “less healthy” foods over time to see how they differed.

Foods and drinks were chosen from UK Consumer Price Index (CPI), which the government uses to track the prices of commonly bought and used goods and services every quarter to measure inflation. The researchers used only those foods and drinks which remained in the survey between 2002 and 2012, and that did not include an element of service (for example a meal in a pub). They also excluded non-calorie containing foods such as tea bags, coffee and mineral water. This left them with 94 foods and drinks, and they obtained an average cost for each item for each year.

The researchers also obtained weight of the items where this was reported in CPI, or estimated the weight based on information on prices for similar items online, or for items with varying weights (such as individual fruit) by using the US Department of Agriculture’s National Nutrient Database standard reference weights.

The nutrient contents of the items was obtained using the UK Department of Health’s National Diet and Nutrition Survey. This survey includes detailed nutritional information on the foods eaten by 1,491 adults. The researchers identified the best match or matches to each of their 94 items from the survey. In some cases there were multiple similar items – for example, if the CPI item was a potato, the survey could contain nutritional information on boiled, baked, and fried potatoes. In these cases the researchers took the average nutritional values. The weight and nutritional information per weight data allowed researchers to calculate costs of each item per 1,000 kilocalories (kcal).

Foods were classified into categories in the Eatwell Plate:

  • bread, rice, potatoes and pasta
  • fruit and vegetables
  • milk and dairy foods
  • meat, fish, eggs, beans and other sources of protein
    food and drinks high in fat and /or sugar

The researchers also used a Department of Health tool which assigns an overall score to foods based on their level of nutrients per 100g, which allows classification of foods as “more healthy” or “less healthy” based on their score.

The researchers used statistical tests to see if the prices of the “more healthy” and “less healthy” foods, or different Eatwell categories differed over time.

 

What were the results of the study?

Average prices for both more and less healthy food rose by 35% between 2002 and 2012, from £3.87 per 1,000kcal to £5.21 per 1,000kcal.

Price per 1,000kcal was always highest for fruit and veg, lowest for starchy foods (bread, rice, potatoes and pasta), and second lowest for foods and drinks high in fat and/or sugar. The price of starchy foods per 1,000kcal stayed roughly the same between 2002 and 2012, while the other groups showed price rises. Each of the food categories, with the exception of fruit and veg, contained both foods classified as more healthy and some as less healthy.

Healthier foods increased in price per 1,000kcal more rapidly than less healthy foods. Healthier foods increased in price by an average of 17 pence per 1,000kcal per year while less healthy foods rose seven pence per 1,000kcal per year.

In 2012 the average price of more healthy foods was about three times higher – £7.49 for 1,000kcal compared to £2.50 for 1,000kcal of less healthy foods.

 

How did the researchers interpret the results?

The researchers concluded that “Since 2002, more healthy foods and beverages have been consistently more expensive than less healthy ones, with a growing gap between them.” They say that this trend may worsen social inequalities in health, and affect the population’s health as a whole. They also suggest that the findings support routinely monitoring food prices to inform possible economic policy responses.

 

Conclusion

The current study has found that the price of food per calorie in the UK between 2002 and 2012 was consistently higher for healthier food than for less healthy food. The suggestion is that this may affect people’s food choices, and therefore their long term health.

The method the researchers used took advantage of routinely available government data on food prices and nutritional content. This means it would not require collection of new data to keep track of healthy and unhealthy food prices per calorie.

There are some limitations to the findings, which the authors themselves discuss, including the small number of foods and drinks they assessed, as they were restricted to using those listed in the UK Consumer Price Index between 2002 and 2012. However, the index includes commonly bought items.

They assessed price per calorie, rather than price per unit weight, as this is the way international organisations assess food poverty. Also dietary recommendations are given in terms of calories rather than weight of food. However, one of the reasons for less healthy foods to be classed as less healthy is that they have high levels of calories per gram. So it is perhaps not surprising that less healthy food tends to costs less per calorie than more healthy foods such as fruit and veg, which tend to have fewer calories per gram. Building on this research to estimate the price of healthy and unhealthy diets as a whole, or also presenting prices per weight could help in giving an idea of the practical day to day impact of these differences.

This study has added another layer to the information available about food prices in the UK, linking it to nutritional value. Given the recent economic climate and also concerns about diet-related health conditions, this is likely to be of interest to both the public and policy makers.  

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Healthy food now costs three times as much as junk, study shows. The Independent, October 8 2014

How eating healthily can triple your shopping bill: Average price of eating 1,000 calories of healthy food reaches £7.49. Daily Mail, October 9 2014

Healthy diet costs three times that of junk food. The Daily Telegraph, October 9 2014

Links To Science

Jones NRV, Conklin AI, Suhrcke M, et al. The Growing Price Gap between More and Less Healthy Foods: Analysis of a Novel Longitudinal UK Dataset. PLOS One. Published online October 8 2014

Categories: NHS Choices

Questions about life after death remain unanswered

Wed, 08/10/2014 - 13:00

“Life after death is a real phenomenon,” Metro reports – but the headline is pure hype. Researchers were actually looking at “near-death experiences” – a very different thing. Indeed, the research involved people who did not die (even “technically”).

Near-death experiences are reported by people claiming to have had experiences when they were close to death, such as when their heart stops during a cardiac arrest.

Reported near-death experiences can range from the mystical (seeing a bright light) or having an out-of-body experience (feeling like you’re floating above your body), to the disturbing (a drowning sensation).

The study involved 140 people who had recovered from a cardiac arrest. Of these, 55 reported having a near-death experience during their cardiopulmonary resuscitation (CPR).

To assess the accuracy of claims of “out-of-body experiences”, researchers put shelves in hospital rooms where cardiac arrests were likely to occur, and placed one image on each shelf that could only be seen from above. One person recalled looking down from the top corner of the room. His descriptions appear to be accurate, but cannot be validated as his treatment occurred in an area without the shelves and pictures.

This study certainly does not provide proof of life after death. It suggests, but provides little evidence, that levels of awareness during CPR may be higher than expected.

 

Where did the story come from?

The study was carried out by researchers from the State University of New York at Stony Brook, the University of London, the University of Southampton and various other UK, US and Austrian Universities. It was funded by Resuscitation Council (UK), the Nour Foundation and the Bial Foundation.

The Bial Foundation says its mission is to “foster the scientific study of the human being from both the physical and spiritual perspectives”.

The Nour Foundation says that its “central goal” is to “stimulate an objective and intelligent discourse on existential questions from an unbiased and interdisciplinary perspective that is rooted not only in theories, but in shared commonality of personal experience as well.”

The study was published in the peer-reviewed medical journal Resuscitation.

The media have all reported that these experiences occurred when the brain had “stopped” or “completely shut down”, when in fact all the people in the study were receiving CPR during the time of the experience, and so had oxygenated blood being pumped around their brain. Therefore, none of the claims around proof of an “afterlife” are strictly true.

A more accepted definition of death is when brain stem death occurs, which is when all neural activity in the deepest brain ceases. While it is possible to keep the heart functioning using life support systems, a person with brain stem death has permanently lost the potential for consciousness.

The existence of an “afterlife” remains a matter of belief, not scientific proof.

 

What kind of research was this?

This was an observational study that aimed to objectively assess reports of awareness and the broad range of mental experiences during CPR, including out-of-body experiences.

 

What did the research involve?

15 hospitals in the US, UK and Austria participated in the study between July 2008 and December 2012. To assess reports that people can look down on themselves from above, the hospitals installed shelves in places where cardiac arrests were likely to occur, such as the emergency department and acute medical wards, and placed one image on each shelf that could only be seen from above. These images included nationalistic and religious symbols, people, animals and major newspaper headlines. A triangle was placed on the underside of the shelf, so that they could assess whether patients looked up after recovery or had had their eyes open during cardiac arrest.

Participants were over 18 and had had a cardiac arrest – defined as no heartbeat or breathing, in or out of hospital with cardiopulmonary resuscitation (CPR) still occurring by the time they were in the emergency department. They had to be considered unconscious with a Glasgow Coma Scale Score of 3/15, meaning that they were unresponsive to pain. If they survived, and were well enough to be interviewed according to their doctor and family, then they were asked to participate.

A research nurse conducted a first general interview, preferably when the person was still in hospital, but some interviews were conducted over the phone. The second interview included the 16-point Greyson Near Death Experience (NDE) Scale, which asks questions including:

  • Did you have the impression that everything happened faster or slower than usual?
  • Did scenes from your past come back to you?
  • Did you see, or feel surrounded by, a brilliant light?
  • Did you see deceased or religious spirits?

An in-depth interview was conducted in those people who had detailed visual and sound experiences while they had a cardiac arrest.

 

What were the basic results?

There were 2,060 recorded cardiac events, and 330 people (16%) survived to hospital discharge. An interview was possible for 140 of them, and 101 completed two interviews. All of those who reported a near-death experience had at least two interviews, while nearly half of those who reported no such experience dropped out after the first interview.

The inpatient interviews took place between three days and four weeks after the event and the telephone interviews took place between three months and a year after the event.

There were 55 people (39%) who remembered something from the time that they were considered to be unconscious. There were no significant differences in age or sex between people who remembered something and those that didn’t.

Of the 101 people who completed the Greyson NDE Scale:

  • 27 had the impression that everything happened faster or slower than usual
  • 22 had a feeling of peace or pleasantness
  • 13 felt their senses were more vivid than usual
  • 13 felt separated from their body

Nine people experienced enough of the items on the scale strongly enough that they were classified as having a near-death experience.

Seven of these people had no auditory (sound) or visual recall, whilst the remaining two people described full visual and sound awareness. One was unable to complete an in-depth interview due to ill health, but the other male participant, aged 57, recalled looking down from the top corner of the room.

His descriptions of the people, sounds and the use of a defibrillator twice during his resuscitation appeared to be accurate, according to his medical records.

Unfortunately, his cardiac arrest occurred in an area without the pictures and the shelves (as did 78% of the cardiac arrests in the study), so the researchers were unable to determine whether he actually did have an out-of-body experience.

 

How did the researchers interpret the results?

The researchers concluded that people who survived cardiac arrest “commonly experience a broad range of cognitive themes, with 2% exhibiting full awareness. This supports other recent studies that have indicated consciousness may be present despite clinically undetectable consciousness. This together with fearful experiences may contribute to PTSD [post-traumatic stress disorder] and other cognitive deficits” following cardiac arrest."

 

Conclusion

This study set out to objectively test reports of awareness and the broad range of mental experiences during CPR, including people being able to look down at their body from above.

The study found that 39% of the survivors who agreed and were well enough to be interviewed remembered experiences while they appeared to be unconscious during CPR. This is probably due to the fact that although the participants had no heartbeat or spontaneous breathing, they were all receiving CPR, which means that their brains were still receiving oxygenated blood.

Only two people described full visual and sound awareness, and one of these was well enough to be interviewed, and described events in line with his medical records.

Other limitations of the study noted by the authors include:

  • potential recall bias due to the amount of time between the event and when the interviews were able to be conducted
  • the limited number of people who survived and had memories of the event
  • the small number of people meant that they were not able to adjust the results for other possible confounders, which could have impacted on the blood flow in the brain. These include the length of time the cardiac arrest continued, the quality of the resuscitation, whether it happened in or out of hospital, the heart rhythm and the use of hypothermia during the cardiac arrest

It is perfectly plausible that people would continue to have thoughts and experiences while there is still oxygenated blood flowing to the brain.

Overall, this study provides no evidence to support the existence of an afterlife, merely that people near death may still have memorable experiences.

Analysis by
Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Out of body experiences: Life after death is a real phenomenon, British scientists find. Metro, October 7 2014

Life after death? Largest-ever study provides evidence that 'out of body' and 'near-death' experiences may be real. The Independent, October 7 2014

First hint of 'life after death' in biggest ever scientific study. The Daily Telegraph, October 7 2014

Does astounding new evidence prove there's life after death? (For at least three minutes). Daily Mirror, October 7 2014

Have scientists proved there is life after death? Research into 'near-death' experiences reveals awareness may continue even after the brain has shut down. Mail Online, October 7 2014

Links To Science

Parnia S, Spearpoint K, de Vos G, et al. AWARE – AWAreness during REsuscitation – A prospective study. Resuscitation. Published online October 6 2014

Categories: NHS Choices

Vaginal orgasm 'doesn't exist', researchers argue

Wed, 08/10/2014 - 12:00

"There is no such thing as a vaginal orgasm," says the Mail Online, in a story that suggests some women have been diagnosed with sexual disorders based on the "myth" that they can orgasm through vaginal intercourse alone.

The news comes from a review of existing (not new) evidence, and its authors make some very bold assertions.

The researchers' main conclusion – that the vaginal orgasm does not exist – is based on their assertion that the vagina has no anatomical structure that can cause an orgasm.

In their opinion, this makes it impossible for a woman to achieve orgasm through penetrative sex alone.

However, they argue there are other effective methods for women to achieve orgasm, such as masturbation and oral sex.

If these arguments are true, it raises a couple of interesting related points. Foremost is the possibility that female sexual dysfunction, where a woman is unable to achieve an orgasm, may not be a "condition" at all if she is only experiencing the problem with penetrative sex.

Men who feel they have premature ejaculation problems because they are unable to "last" long enough to bring their partner to orgasm may in fact be unaware that their partner may not be able to orgasm through penetrative sex.

This is an interesting, if complex and unsupported, review of a subject of eternal fascination to the media – sexual arousal and orgasm in women.

Still, the main thrust of the researchers' argument – that penetrative sex is not the be all and end all of sexual activity – is a valid and reasonable one.

 

Where did the story come from?

The study was carried out by researchers from the Italian Centre of Sexology and the University of Florence. There is no information about any external funding.

It was published in the peer-reviewed journal Clinical Anatomy on an open-access basis, so it is free to read online.

The Mail Online went to town on the story, but its claim that, "for years women have often declared they can either orgasm through sex or foreplay" is not based on any evidence.

It also does not make it clear that this was an opinion piece summarising existing evidence and not research based on new evidence.

But, overall, the website made a fairly decent job of summarising some complex findings.

 

What kind of research was this?

This was a narrative review looking at the anatomical and physiological basis of female orgasm.

The authors say orgasm is a normal psychophysiological function and, in a statement of the rather obvious, women have the right to feel sexual pleasure.

For this reason, they say it is important that explanations of orgasm are based on female biology and not on hypotheses or personal opinion.

They also say some researchers have proposed a new "anatomical terminology" for the female sexual response, including an "inner clitoris" linked to the "G-spot". Their paper aims to clarify whether these new terms have a scientific basis.

A narrative review discusses and summarises the literature on a particular topic. As these reviews do not provide detailed information on the criteria for inclusion of the studies discussed, they are not considered as rigorous or reliable as systematic reviews.

With a narrative review, there is always the danger that "cherry-picking" of research may have taken place – where evidence that supports the authors' position is included, but contradictory evidence is ignored.

 

What does the review say?

The authors' main points were:

  • The "inner clitoris" suggested by some researchers does not exist. The entire clitoris is an external organ, composed of the glans, body and root (or crura).
  • There is no anatomical basis for a "clitoral-urethro-vaginal complex" (which others claim supports the idea of the "G-spot").
  • The vagina has no anatomical relationship with the clitoris.
  • There is no scientific basis for the existence of the G-spot, although it has become the centre of a "multimillion-dollar business" – for example, through surgical procedures that claim to help "enhance" the G-spot.
  • The vaginal orgasm does not exist.
  • The female erectile tissue responsible for orgasms is composed of the clitoris and its vestibular bulbs, the pars intermedia, labia minora and corpus spongiosum (of the female urethra). This, say the authors, corresponds to the penis in men and can be called the "female penis".
  • "Female orgasm" is the scientific term that should be used for all orgasms in women.

 

How did the researchers interpret the results?

The authors say that, worldwide, the majority of women do not orgasm during intercourse: "Female sexual dysfunctions are popular because they are based on something that does not exist; the vaginal orgasm."

Yet they say female orgasm is possible in all women if the female erectile organs – as they put it, the "female penis" – are stimulated.

This can happen during a variety of sexual activity, including masturbation, cunnilingus (oral sex) and intercourse (using the hands to stimulate the "female penis" during penetrative or anal sex).

The researchers say many men think long intercourse is the key to female orgasm, but this is not necessarily helpful to women, some of whom "may be grateful to get it over with quickly".

Male ejaculation does not automatically mean the end of sex for women, they say, and they romantically conclude that touching and kissing can be continued almost indefinitely.

 

Conclusion

This is an interesting, if complex, review of a subject of eternal fascination for the media – sexual arousal and orgasm in women. However, despite the authors' claim to the contrary, it is hardly likely to be the last word on the topic.

Some of the points it makes are in line with scientific opinion, which holds that no distinction should be made between "types" of female orgasm.

The "vaginal orgasm" theory – first posited by Freud as the sexual response of "mature" women, achievable through intercourse and separate from the "clitoral orgasm" (for adolescents only) – was criticised by feminists as long ago as the 1970s and is considered an outmoded theory by most experts in sexual medicine.

However, the relationship between the clitoris and the sensitivity of the vagina continues to be the subject of debate.

Many women worry about achieving – or failure to achieve – orgasm. There are many reasons for orgasm problems. Your GP may be able to refer you to a specialist doctor or therapist, who can check for any physical reasons and help with any psychological barriers. Use the NHS Choices search facility to find sexual health services near you.

And, as the authors point out, if penetrative sex is not particularly stimulating, there are other techniques your partner can explore, such as mutual masturbation and oral sex. For more information on good sex tips, see Talking about sex.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

The vaginal orgasm doesn't exist - it's the clitoris that holds the key to female pleasure, study claims. Mail Online, October 7 2014

'Final' word on female orgasm is an anti-climax. New Scientist, October 7 2014

There's no such thing as a vaginal orgasm! Salon, October 7 2014

Links To Science

Puppo V, Puppo G. Anatomy of sex: Revision of the new anatomical terms used for the clitoris and the female orgasm by sexologists. Clinical Anatomy. Published online October 6 2014

Categories: NHS Choices

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